ECAT Physics Fluid Dynamics Chapter Online Test

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Physics

1. If A x B = B x A, then the angle between A and B is

π/3

π

π/4

π/2

2. A body whose momentum is constant, must have constant:

Force

None of these

Velocity

Acceleration

3. The two thin tubes which show most correctly the behavior of water are

4 and 5

2 and 3

1 and 2

3 and 4

4. A truck and a car are moving with equal velocity. On applying the brake both will stop after certain distance then

Car will cover less distance before rest

Truck will cover less distance before rest

Both will cover equal distance

None of these

5. A tube is tapered from 20 cm diameter to 2 cm diameter, the velocity at the first cross-section is 50 cm/s, then the velocity at the second cross-section is

5 m/s

50 m/s

5 cm/s

50 cm/s

6. The unit of Planck’s constant h is same as that of

Energy

Linear momentum

Work

Angular momentum

7. Distance traveled by a body falling from rest in the first, second and third second is in the ratio of

1 : 3 : 5

1 : 4 : 9

1 : 2 : 3

None of these

8. Which of the following statements for an object in equilibrium is not true?

The object must be at rest

The acceleration of the object is zero

The object is moving at constant speed

The object can be at rest

9. Wb/m² is equal to

Henry

Watt

Tesla

Dynes

10. The velocity of falling raindrops attains limited value because of

Up thrust of air

Viscous force exerted by air

Air currents of the earth atmosphere

Surface tension effect

11. A man fires a bullet of mass 200 g at a speed of 5 m/s. The gun is of one kg mass. By what velocity the gun rebounds backwards?

0.01 m/s

1 m/s

0.1 m/s

10 m/s

12. Numerical value of magnitude of a physical quantity is

Either (B) or (C)

Independent of system of units

Inversely proportional to magnitude of the unit

Directly proportional to magnitude of the unit

13. A ball of mass m₁ and another ball of mass m₂ are dropped from equal heights. If time taken by the balls are t₁ and t₂ respectively then

t₁ = t₂/4

t₁ = t₂/2

t₁ = t₂

t₁ = 4t₂

14. A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of particle. The motion of the particle takes place in a horizontal plane. It follows

Velocity is constant

It moves in a circular path

None of these

Linear momentum is constant

15. The mass of fluid passing through any cross-section per unit time is called

Mass flux

Electric flux

Magnetic flux

Both a and b

16. The blood pressure of the person

Decreases with age

Remains the same

None

Increases with age

17. An instrument called a sphygmomanometer measure

None of these

Density of water

Milk density

Blood pressure

18. When a bicycle is in motion but not pedaled, the force of friction exerted by the ground on the two wheels is such that it acts

In the backward direction on the front wheel and in the forward direction on the rear wheel

In the backward direction on both the wheels

In the forward direction on the front wheel and in the backward direction on the rear wheel

In the forward direction on bath the wheels

19. Angular momentum has the same unit as

Linear momentum x time

Work x frequency

Impulse x distance

Power x time

20. The term Brownian movement refers to

Convection currents in a liquid or gas

Irregular motions of small particles suspended in a fluid

Convection currents in a gas but not in a liquid

The stretching of a body beyond its elastic limit

21. For keeping a body in circular motion, the force required is

Radial

Centrifugal

Tangential

Centripetal

22. A body is floating in a liquid. The up thrust on the body is

Less than the weight of liquid displaced

Weight of body-weight of liquid displaced

Equal to weight of liquid displaced

Zero

23. Surface area is

Scalar

Both scalar and vector

Neither scalar nor vector

Vector

24. With the increase of temperature viscosity

Increase

Remains same

Doubles

Decrease

25. When torque acting upon a system is zero which of the following will be constant?

Linear momentum

Force

Linear impulse

None of these

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26. If the K.E. of a body becomes four times of the initial value, then new momentum will

Become twice its initial value

Become four times, its initial value

Become three times, its initial value

Remains constant

27. The resultant of two equal force is double of either of the force. The angle between them is

90°

120°

60°

0°

28. The terminal velocity of for a water droplet of radius 10¯⁵ m is of the order of

1 cm/s

1 nm/s

1 mm/s

1 μm/s

29. A projectile on its path gets divided into two pieces at its highest point. Which is true?

Kinetic energy decreases

Kinetic energy increases

Momentum increases

Momentum decreases

30. If speed of electron is 5 x 10⁵ m/s. How long does it take one electron to traverse 1 m?

1 x 10⁵ s

1 x 10⁶ s

2 x 10⁵ s

2 x 10⁶ s

31. If L and R represent inductance and resistance respectively, then dimensional formula of L/R will be

MLT⁰

M⁰LT²

M⁰L⁰T²

ML⁰T⁰

32. The energy associated with an electron of velocity 10⁶ m/s is:

3 x 10¯¹⁹ J

4.5 x 10¯¹⁰ J

3 x 10¯¹⁰ J

4.5 x 10¯¹⁹ J

33. A jet engine works on the principle of

Conservation of energy

Conservation of linear momentum

Conservation of mass

Conservation of angular momentum

34. The unit of inductance is equivalent to

Ampere/volt x second

Volt/ampere x second

Volt x second/ampere

Volt x ampere/second

35. The minimum force required to move a body of mass m vertically upward is:

Mg/2

More than mg

More than 2mg

Mg

36. Two forces of magnitude 7 N and 5 N act on a particle at an angle θ to each other, θ can have any value. The minimum magnitude of the resultant force is

8 N

2 N

5 N

12 N

37. Viscosity of glycerin at 30° C in Nsm¯²

6.18 x 10¯³

6.49 x 10¯³

6.29 x 10¯³

6.12 x 10¯³

38. If an iron ball and a wooden ball of the same radius was released from a height ‘h’ in vacuum, then time taken by both of them to reach ground will be

Zero

Unequal

Roughly equal

Exactly equal

39. The escape velocity from the earth’s surface is 11 km/s. A certain planet has a radius twice that of the earth but its mean density is the same as that of the earth. The value of the escape velocity from this planet would be:

16.5 km/s

22 km/s

11 km/s

5.5 km/s

40. The Systolic blood pressure comes when

Cutting off the blood flow

All of these

None of these

Vessel collapse

41. An airplane flies 400 m from north and then flies 300 m south and then flies 1200 m unwards then net displacement is

1300 m

1200 m

1400 m

1500 m

42. Velocity of fluid increases where the pressure is

Constant

Changes continuously

High

Low

43. Which of the following sets of concurrent forces may be in equilibrium?

F₁ – 3 N, F₂ – 5 N, F₃ = 1 N

F₁ – 3 N, F₂ – 5N, F₃ = 15 N

F₁ – 3 N, F₂ – 5N, F₃ = 6 N

F₁ – 3 N, F₂ – 5 N, F₃ = 9 N

44. When body moves with terminal velocity the acceleration in the body become

Maximum

Infinite

Variable

Zero

45. Two forces P and Q have a resultant perpendicular to P. The angle between the forces is:

sin¯¹(P/Q)

tan¯¹(P/Q)

tan¯¹(-P/Q)

cos¯¹(-P/Q)

46. A body of mass 1.0 kg is falling with an acceleration of 10 m/s². Its apparent weight will be (g = 10 m/s²)

0.5 kg wt

2.0 kg wt

1.0 kg wt

Zero

47. A person is standing on a rotating stool spreading his arms. He suddenly contracts his arms. His

Angular momentum increases

Angular momentum decreases

Moment of inertia decreases

Moment of inertia increases

48. In a surface tension experiment with a capillary tube water rises up to 0.1 m. If the same experiment is repeated on an artificial satellite, which is revolving around the earth, water will rise in the capillary tube up to a height of

0.2 m

0.1 m

Full length of the capillary tube

0.98 m

49. The Drag force increases as the speed of the object

Decreases

Decreases rapidly

None of these

Increases

50. The torque acting on a body is the rotational analogue of

Force in linear motion

Mass of the body

Linear kinetic energy of the body

Linear velocity of the body

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51. The length breadth and thickness of a block are given by 1 = 12 cm, b = 6 cm and t = 2.45 cm, the volume of the block according to the idea of significant figures should be:

None of these

1 x 10² cm³

1.763 x 10² cm³

2 x 10² cm³

52. When a bicycle is in motion, the frictional forces exerted by the ground are:

In the forward direction on the rear wheel

In the forward direction on both the wheels

In the backward direction on the front wheel and the forward direction on the rear wheel

In the backward direction on both the wheels

53. The pressure will be low where the speed of the fluid is

Constant

Low

Zero

High

54. Dot product of two mutual perpendicular vector is:

None of these

0

∞

1

55. The acceleration of a motor car is 8 m/s². If the diameter of its wheel be 2 meter, its angular acceleration will be

8 m/s²

8 radian/s²

16 m/s²

16 radian/s²

56. A person walks first 10 km north and 20 km east, then the resultant vector is

20 36 km

22.36 km

25.23 km

22.46 km

57. A particle is moving in a vertical circle. The tensions the string when passing through two positions at angles 30° and 60° from vertical (lowest positions) are T₁ and T₂ respectively. Then

T₂ > T₁

Tension in the string always remains the same

T₁ = T₂

T₁ > T₂

58. At high speeds the force is no longer

Simply proportional

None of these

Proportional

No proportion

59. The dimensions of the quantities in one of the following pairs are the same. Identify the pairs.

Energy and Young’s modulus

Angular momentum and work

Torque and work

Light year and time

60. A particle of mass ‘m’ at rest is acted upon by a force ‘P’ for a time ‘t’. Its kinetic energy after an interval ‘t’ is

Pt/2m

P²t²/3m

P²t²/2m

P²t²/m

61. The centripetal force for a car moving on a road is given by

Friction due to tyres

Force by steering wheel

Force of brakes

The drive of the car

62. The Bernoulli’s equation is based on the

All of these

Law of conservation of energy

Law of conservation of mass

Law of conservation of momentum

63. Angular momentum of a body is defined as the product of

Centripetal force and radius

Mass and angular velocity

Moment of inertia and angular velocity

Linear velocity and angular velocity

64. A railway engine (mass 10⁴ kg) is moving with a speed of 73 km/h. The force which should be applied to bring it to rest over a distance of 20 m is

100,000 N

10,000 N

7,200 N

3,600 N

65. Two bodies of mass 1 kg and 2 kg have equal momentum. Then, the ratio of their kinetic energies is

3 : 1

1 : 3

2 : 1

1 : 1

66. A car travels first half distance between two places with a speed of 30 km/h and remaining half with a speed of 50 km/h. The average speed of the car is

10 km/h

40 km/h

37.5 km/h

42 km/h

67. The motion of planets in the solar system is an example of conservation of:

Angular momentum

Kinetic energy

Momentum

Mass

68. If the force applied is F and the velocity gained is v, then the power developed is

v/F

F/v

Fv

Fv²

69. The pressure will be low where the speed of the fluid is

Zero

Low

Constant

High

70. A motorcycle driver double its velocity when he is having a turn. The force exerted outwardly will by

¼ time

Double

Half

4 times

71. Viscosity of acetone at 30° C in Nsm¯²

0.224 x 10¯³

0.301 x 10¯³

0.198 x 10¯³

0.295 x 10¯³

72. The rain drop falling from the sky reach the ground with

Variable speed

Variable acceleration

Constant terminal velocity

Constant acceleration (g)

73. Swimming is based on the principle of

Newton’s 2nd law

Newton’s 1st law

All

Newton’s 3rd law

74. A body of mass 5 kg is moving with a momentum of 10 kg m/s. A force of 0.2 N acts on it in the direction of motion of the body for 10 seconds. The increase in its kinetic energy is

2.8 joule

3.8 joule

3.2 joule

4.4 joule

75. If an object weighs 90 N in air, 60 N in water, and 20 N in an unknown liquid in which it does not dissolve, the so. Gr. Of the unknown liquid is

1.5

1.3

3.0

2.3

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76. At high altitude the blood oozes out of the nose and near because

The percentage of oxygen in the air increase

The blood pressure increase at high altitudes

The density of blood decreases at high altitudes

The atmospheric pressure decreases there

77. The high blood pressure is

120 torr

130 torr

100 torr

110 torr

78. The vector sum of two forces is perpendicular to their vector difference. In that case, the forces

Are equal to each other in magnitude

Are equal to each other

Cannot be predicted

Are not equal to each other in magnitude

79. Fire fighters have a jet attached to the head of their water pipes in order to:

Avoid wastage of water

Increase the volume to water flowing out

Increase the volume to water flowing per second

Increase the mass of water flowing per second

80. Which of the following quantities is a vector

Displacement

Density

Temperature

Volume

81. Surface tension of water is reduced by adding

Both A and B

Detergents

Camphor

Plastic

82. If a force acts on a body, whose action line does not pass through its center of gravity, then the body will experience

No acceleration

Angular acceleration

None of these

Linear acceleration

83. Drag force is given by

Newton’s law

Gauss law

Pascal’s law

Stokes law

84. A chimney works best if air exposed to the chimmey is

Moving

Moving fast

Stationary

Moving slowly

85. A particle is moving in a circle with uniform speed v. In moving from a point to another diametrically opposite point,

The kinetic energy changes by mv²

The momentum changes by mv

The kinetic energy changes by (1/2)mv²

The momentum changes by 2mv

86. You are on a frictionless horizontal plane. How can you get off if no horizontal force is exerted by pushing against the surface?

By spitting or sneezing

By rolling your body on the surface

By jumping

By running on the plane

87. Which of the following is true?

Neither momentum nor kinetic energy is conserved in inelastic collisions

Both momentum and kinetic energy are conserved in all collisions

Momentum is conserved in all collisions but kinetic energy is conserved only in inelastic collisions

Momentum is conserved in all collisions but not kinetic energy

88. Even the small viscosity of the air causes a retarding force on car at high speed is

Very large

Large

None of these

Small

89. The direction of the angular velocity vector is along

The inward radius

The tangent to the circular path

The outward radius

The axis of rotation

90. The number of significant figures in all the given number 25.12, 2009, 4.156 and 1.257 x 10¯⁴ is

2

3

4

1

91. What is true between center of gravity and center of mass?

They are always at the same point

Center of gravity changes as one goes away from the earth but center of mass remains same

None of these

Center of mass changes but center of gravity is always same

92. Two force are such that then sum of their magnitudes is 18 N and their resultant is perpendicular to the smaller forces and the magnitude of resultant is 12. Then the magnitude of the forces are.

10 N, 8 N

12 N, 6 N

16 N, 2 N

13 N, 5 N

93. The concentration of red blood cells in blood is

~ 50%

– 40%

– 45%

~ 30%

94. Two water pipes of diameters 2 cm and 4 cm are connected with main supply line. The velocity of flow of water in the pipe 2 cm diameter is

¼ times

4 times

½ of 4 cm diameter pipe

Twice

95. Terminal velocity of the body is directly proportional to the

Size of the body

Radius of the body

Diameter of the body

Square of the diameter of the body

96. A cold soft drink is kept on the balance. When the cap is opened, then the weight

Decreases

First increases, then decreases

Remains same

Increases

97. At the top of the trajectory of a projectile, the directions of its velocity and acceleration are

Antiparallel to each other

Parallel to each other

Inclined to each other at an angle of 45°

Perpendicular to each other

98. Force of friction is present in

All of these

Solid

Gases

Liquid

99. Two forces of 4 dyne and 3 dyne act upon a body. The resultant force on the body can only be

Between 3 and 4 dyne

More than 4 dynes

More than 3 dynes

Between 1 and 7 dyne

100. If unit of length, mass and time each be double, the unit of work done is increased by

4 times

8 times

2 times

6 times

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101. Angular momentum is

At 45° angle

Scalar

Polar vector

Axial vector

102. In case of streamed lined flow of liquid, the loss of energy is

Maximum

Minimum

Equal to what is in turbulent flow

Infinite

103. As the droplet accelerates the net force acting on it is

Zero

Increase

Decreases

None of these

104. The unit of focal power of a lens is

Horse power

Diopter

Kilo watt

Watt

105. Burnoullis equation is obtained by applying law of conservation of _________.

Momentum

Fluid

Energy

Mass

106. Which of the following is not a perfectly inelastic collision?

An electron captured by a proton

A bullet striking a bag of sand

Striking of two glass balls

A man jumping onto a moving cart

107. Equation of continuity is obtained by apply in law of conservation of

Energy

Mass

Momentum

All

108. A stone is dropped from rest from the top of a tower 19.6 m high. The distance traveled during the last second of its fall is (giving g = 9.8 m/s²)

9.8 m

19.6 m

14.7 m

4.9 m

109. A chimney works best when it is

Not tall but wide

A and B

Tall

Exposed to air currents

110. Water is filled up to a height ‘H’ in a tank. A hole is made at depth ‘H’ below the water level. The velocity of efflux of the fluid is.

√gh

2gh

.gh

√2gh

111. For a given angle of projection, if the time of flight of a projectile is doubled, the horizontal range will increases to:

Once

Twice

Four times

Thrice

112. The kinetic energy of a body becomes four ties its initial value. The new linear momentum will be

Four times the initial value

Same as the initial value

Thrice the initial value

Twice the initial value

113. The equation of continuity of fluid is based on the

Law of conservation of momentum

Law of conservation of mass

Law of conservation of energy

All of these

114. Reason of weightlessness in a satellite is

None of these

Zero reaction force by satellite surface

Center of mass

Zero gravity

115. A body is subjected to a force such that its velocity is doubled, then

Its momentum is also doubled

Its acceleration is also doubled

Its kinetic energy is also doubled

Its potential energy is also doubled

116. A ball is dropped from a certain height and another ball is projected horizontally from the same point. Which of the following statements is correct?

Both hit the ground at the same speed

The change of velocity during the path for both balls is the same

Both hit the ground at the same velocity

The change of speed during the path for both balls is the same

117. Viscosity of ethanol at 30° C in Nsm¯²

1.014 x 10¯³

0.954 x 10¯³

1.000 x 10¯³

1.012 x 10¯³

118. The apparent loss in weight of the block in the liquid is

30 N

15 N

60 N

21 N

119. Identify the pair whose dimensions are equal

Stress and energy

Torque and work

Force and stress

Force and work

120. A thief stole a box with valuable article of weight W and jumped down a wall of height h. Before he reached ground he experienced a load of

W/2

W

2W

Zero

121. Coefficient of viscosity of honey is greater than

Petrol

Alcohol

Milk

Water

122. If the water falls from a dam into a turbine wheel 19.6 m below, then the velocity of water at the turbine, is (Take g = 9.8 m/s²)

39.2 m/s

19.6 m/s

98.0 m/s

9.8 m/s

123. The flow is said to be streamline or laminar when every particle

Moves along the same path as

None of these

Moves in different direction

Slowly moves in one direction

124. The ratio of the numerical values of the average velocity and average speed of a body is always.

Less than unity

Unity or more

Unity

Unity or less

125. Water is filled up to a height ‘H’ in a tank. A hole is made at depth ‘h’ below the water level. The velocity of efflux of the fluid is

√2gh

2gh

gh

√gh

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126. The atmosphere is held to the earth by

The rotation of earth

Gravity

Winds

Clouds

127. A 50 kg man with 20 kg load on his head climbs up 20 steps of 0.25 m height each. The work done in climbing is

100 J

3430 J

5 J

350 J

128. Two insoluble objects seem to lose the same weight when completely submerged in a liquid. The objects must have the same

Density

Weight in water

Weight in the liquid

Weight in air

129. The electrical forces between the molecules of a liquid are

Both A and B

Repulsive

None

Attractive

130. A flowing liquid possesses

K.E.

All

P.E.

Pressure Energy

131. The K.E. of a light and a heavy object is same. Which object has maximum momentum?

Light object

Both have the same momentum

Data is not sufficient

Heavy object

132. Stoke’s law is applicable to

Motion through horizontal surface

Motion through non-resistive medium

Motion through viscous medium

Motion through free space

133. If the spinning speed of the earth is increased, then the weight of the body at equator

Decreases

Doubles

Increases

Does not change

134. Two bodies of masses 1 kg and 5 kg are dropped gently from the top of a tower. At a point 20 cm from the ground both the bodies will have the same

Total energy

Kinetic energy

Momentum

Velocity

135. A flowing liquid possesses

K.E.

P.E.

All

Pressure Energy

136. The low blood pressure is known as

Diastolic

Low blood pressure

None of these

Systolic

137. With increase of temperature, the viscosity of liquid and gases

Increase for liquids and decreases for gases

Increases for both

Decrease for both

Decrease for liquids and increase for gases

138. When fluid is incompressible then

Density of the fluid is constant

Volume of the fluid is constant

Velocity of the fluid is constant

Flow of the fluid is straight line

139. If water rises 4 cm in a long, thin tube because of capillary action, then, under corresponding conditions of use, the rise (in the tube) of a liquid whose density is 2 glcm³ will be

None

8 cm

1 cm

2 cm

140. A body moving in a circular path with constant speed has

Constant retardation

Variable speed and constant velocity

Constant acceleration

Variable acceleration

141. The maximum velocity of an object falling freely through air is called

Terminal velocity

Final velocity

Initial velocity

Instantaneous velocity

142. The momentum of particle is numerically equal to its kinetic energy. What will be the velocity of the particle?

4 m/s

2 m/s

None of these

1 m/s

143. The maximum and minimum magnitudes of the resultant of two given vectors are 17 units and 7 units respectively. If these two vectors are at right angles to each other, the magnitude of their resultant is

13

16

14

18

144. V = √2g(h₁ – h₂) shows the

Equation of continuity

None of these

Bernoulli’s theorem

Torricelli’s theorem

145. If a particle covers half the circle of radius R with constant speed then

Change in KE is mv²

Momentum change is mvr

Change in KE is ½ mv²

Change in KE is zero

146. The motion of planets in the solar system is an example of the conservation of:

Angular momentum

Energy

Mass

Linear momentum

147. The rectangular components of force 5 dyne are

2.5 and 25 dyne

1 and 2 dyne

2 and 3 dyne

3 and 4 dyne

148. The smooth or steady stream-line flow is know as

None of these

Laminar flow

Both a and b

Turbulent flow

149. If we move from equator to pole, value of g

First A and Then B

Remains same

Decreases

Increases

150. If momentum is increased by 20% then K.E. increases by

77%

55%

44%

66%

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151. A man standing near a fast moving train may fall

Away from the train

On the train

On himself

Towards the train

152. Blood has a density

None of these

Equal to water

Lesser then water

Greater then water

153. In a uniform circular motion

Only velocity change, acceleration remain constant

Kinetic energy remain constant

Speed and acceleration change

Velocity and acceleration remain constant

154. For the same kinetic energy, the momentum is maximum for:

A proton

A deuteron

An α particle

An electron

155. The range of projectile is 50 m when θ is inclined with horizontal at 15°. What is the range when θ becomes 45°?

100 m

300 m

400 m

200 m

156. Unite of impulse in

Joule

Kg m/s

Newton

Kg m

157. A ball is dropped vertically down and it takes time t to reach the ground. At time t/2:

The velocity of the ball was V/3 where V is the velocity when it reached the ground

The ball had covered exactly half the distance

The ball had covered more than half the distance

The ball had covered less than half the distance

158. When the velocity of a liquid flowing steadily in a tube increases, its pressure?

Increases

Decreases

Remains same

Zero

159. Maximum height of a bullet when fired at 30° with horizontal is 11 m. Then height when it is fired at 60° is

7.8 m

6 m

33 m

22 m

160. What is the weight of a 700 g of body on a planet whose mass is 1/7th of that of earth and radius is ½ of earth?

500 gf

700 gf

400 gf

300 gf

161. Height at which value of ‘g’ become one-fourth to hat on earth is:

(3/2)R

R

2R

4R

162. In case of uniform circular motion which of the following physical quantity do not remain constant?

Kinetic energy

Momentum

Mass

Speed

163. When two surfaces are coated with a lubricant, then they

Stick to each other

None of these

Slide upon each other

Roll upon each other

164. The decrease in potential energy of a ball of mass 20 kg which falls from a height 50 cm is:

98 J

1980 J

None of these

968 J

165. A ball whose kinetic energy is E, is thrown at an angle of 45° with the horizontal, its kinetic energy at the highest point of its flight will be

E/2

E

F/√2

Zero

166. A car covers 1/3 distance with speed 20 km/hr and 2/3 with 60 km/h. Average speed is

80 km/h

40 km/h

50√2 km/h

36 km/h

167. At high altitude the blood oozes out of the nose and ear because

The density of blood decreases at high altitudes

The blood pressure increase at high altitudes

The atmospheric pressure decreases there

The percentage of oxygen in the air increase

168. In an elevator moving vertically up with an acceleration ‘g’, the force exerted on the floor by a passenger of mass M is

Mg

2 Mg

½ Mg

Zero

169. According to equation of continuity A1V1 = A2V2 = constant. The constant is equal to

Density of fluid

Mass of fluid

Flow rate

Volume of fluid

170. In a container having water filled up to a height h, a hole is made in the bottom. The velocity of water flowing out of the hole is

Proportional to h¹⁄ ²

Proportional to h²

Independent of h

Proportional to h

171. An aircraft is moving with a velocity of 300 ms¯¹. If all the forces acting on it are balanced, then

It still moves with the same velocity

It will be fall down instantaneously

It will lose its velocity gradually

It will be just floating at the same point in space

172. The kinetic energy of a body of mass 2 kg and momentum of 2 Ns is

2 J

3 J

1 J

4 J

173. If v is the velocity of flow of liquid through a tube of area of cross-section A, then according to equation of continuity

None of these

v/A = constant

A/v = constant

Av = constant

174. Which of the following is not the unit of energy?

Joule

Watt

Calorie

Electron-volt

175. Which of these statements is not correct?

Moment of inertia depends on choice of axes

Moment of inertia does not depend on mass of body

Moment of inertia is independent of shape and size of the body

None of these

Page 8 of 11

176. The blood vessels are inflated even in

Working state between heart beat

Relaxed states between heart beat

Occasionally

None of these

177. In Torricelli’s theorem, the speed of efflux is equal to

h₁ – h₂

(h₁ – h₂) and falling under gravity

None of these

Action of gravity

178. The angular momentum of a body is conserved if

Force acting on it is zero

Torque acting on it is constant

Force acting on it is constant

Torque acting on it is zero

179. Internal friction of fluid is called

Viscosity

Cohesive force

Surface tension

Resistance

180. In equation of continuity, if the fluid is incompressible and the flow is steady, the mass of the fluid is

Somewhat conserved

Conserved

Not conserved

None of these

181. If v is the velocity of flow of liquid through a tube of area of cross-section A, then according to equation of continuity

A/v = constant

v/A = constant

Av = constant

None

182. In case of streamed lined flow of liquid, the loss of energy is

Zero

Maximum

Infinite

Minimum

183. Viscosity of water at 30° C in Nms¯²

0.599 x 10¯³

0.521 x 10¯³

0.564 x 10¯³

0.594 x 10¯³

184. Deep water almost runs still when surface water flow in rivers. What does it explains

Equation of continuity

Bernoulli’s equation

Magnus effect

Surface energy

185. Bernoulli’s equation is applicable for

Both laminar and turbulent flow

Laminar flow

Turbulent flow

None of these

186. Find the total displacement of a body in 8 seconds starting from rest with an acceleration of 20 cm/s²

64 cm

640 cm

0.064 m

64 m

187. At terminal velocity, fluid friction is

Maximum

Zero

Minimum

None of these

188. When the velocity of a liquid flowing steadily in a tube increases, its pressure?

Increases

Zero

Remains same

Decreases

189. If force and displacement of particle in the direction of force are doubled. Work would be

4 times

Half

¼ times

Double

190. Rocket engines lift a rocket from the earth surface, because hot gas with high velocity

Push against the air

Heat up the air which lifts the rocket

Push against the earth

React against the rocket and push it up

191. The maximum drag force on a falling sphere is 9.8 N, it weight is

1 N

4.9 N

Cannot be calculated

9.8 N

192. Which of the following quantity is dimensionless?

Power of lens and gas constant

Gravitational constant

None of these

Plank’s constant

193. The low blood pressure is

75 – 80 torr

79 – 80 torr

78 – 809 torr

70 – 80 torr

194. A body falls freely from rest. It covers as much distance in the last second of its motion as covered in the first three seconds. The body has fallen for a time of

9 s

3 s

7 s

5 s

195. The force exerted by the fluid in a hydraulic press on the piston is 2000 N. If the area of the piston is 10 cm², the fluid pressure on the piston is, in N/cm²

2000

20

200

20,000

196. Which one of the following groups have quantities that do not have the same dimensions?

Velocity, speed

Force, impulse

Work, energy

Pressure, stress

197. S.I unit of magnetic flux is

Weber metre¯²

Weber

Weber per metre

Weber per metre⁴

198. If a train traveling at 72 kmph is to be brought to rest in a distance of 200 meters, then its retardation should be

1 ms¯²

20 ms¯²

10 ms¯²

2 ms¯²

199. Range of a projectile if R, when the angle of projection is 30°. Then, the value of the other angle of projection for the same range, is:

60°

40°

45°

50°

200. The relation P₁ – P₂ = ½ PV₂² shows the

Torricelli’s theorem

None of these

Venturi relation

Bernoulli’s equation

Page 9 of 11

201. Which of the following substances has high resistance to flow?

Thick tar

Honey

Mobile oil

All of these

202. Substance which flows easily are

Water

Petrol

Kerosene oil

All of these

203. In a uniform circular motion (horizontal) of a ball tied with a string, velocity at any time is at any angle θ with acceleration, then θ is

θ = 60°

θ = 90°

None of these

θ = 30°

204. According to Stoke’s law, drag force depends on

Final velocity

Terminal velocity

Initial velocity

Instantaneous velocity

205. Two forces of 12 N and 8 N act upon a body. The resultant force on the body has a maximum value of:

0 N

20 N

4 N

8 N

206. When a horse pulls a cart, the force that makes the horse run forward is the force exerted by

The ground on the cart

The horse on the cart

The horse on the ground

The ground on the horse

207. Which of the following is the smallest unit?

Fermi

Meter

Angstrom

Millimeter

208. Two bullets are fired simultaneously, horizontally and with different speeds from the same place. Which bullet will hit the ground first?

The slower one

Depends on their mass

The faster one

Both will reach simultaneously

209. The fluid which is incompressible and non-viscous is called:

Ideal fluid

All

Non-ideal fluid

Prefect fluid

210. A boat of mass 40 kg is at rest. A dog of mass 4 kg moves in the boat with a velocity of 10 m/s. What is the velocity of boat?

2 m/s

8 m/s

1 m/s

4 m/s

211. Stokes law is applicable if body has ___________ shape.

Square

Spherical

Circular

Rough

212. A pendulum of time period T is kept suspended in a train accelerating uniformly, then its time period

Remains unchanged

Decreases

None of these

Increases

213. Pressure exerted by a gas on the walls of its container is due to

Cohesion between the gas molecules and the container

Adhesion between the gas molecules and the container

Surface tension of the gas

Collision between the gas molecules and the container

214. At systolic pressure, at the point the first surges of blood flow through the narrow stricture produces

High flow speed

Sound heard

Initially turbulent

All of these

215. The terminal velocity of a small size spherical body of radius R moving in a fluid varies as

R

(1/R)²

R²

1/R

216. If the acceleration due to gravity is 10 ms¯² and the units of length and time are changed to kilometer and hour respectively, the numerical value of acceleration in

72000

129600

36000

360000

217. The angular momentum of a system of particles is not conserved

None of these

When net external force is acting upon the system

When a net external impulse is acting upon the system

When a net eternal torque is acting upon the system

218. Length cannot be measured by

Micron

Debye

Light year

Fermi

219. Moment of inertia of an object does not depend upon

Axis of rotation

Mass of object

Mass distribution

Angular velocity

220. A car is moving high velocity when it takes a turn. A force acts on it outwardly because of

Gravitational force

Centripetal force

All of these

Centrifugal force

221. A man sitting in a bus traveling in a direction from west to east with a speed of 40 km/h observes that the rain-drops are falling vertically down. To the another man standing on ground the rain will appear

To fall at an angle going from west to east

To fall at an angle going from east to west

The information given is insufficient to decide the direction of rain.

To fall vertically down

222. A force of 10 N displace an object by 10 m. If work done is 50 J then direction of force makes an angle with direction of displacement.

120°

None of these

60°

90°

223. If rope of lift breaks suddenly. The tension exerted by the surface of life is (a = Acceleration of lift)

Mg

M(g + a)

M(g – a)

0

224. Two bodies with kinetic energies in the ratio of 4 : 1 are moving with equal linear momentum. The ration of their masses is

4 : 1

1 : 1

1 : 2

1 : 4

225. Pick out the wrong pair:

Pressure-barometer

Charge-coulomb

Sp. gravity-hygrometer

Temperature-thermometer

Page 10 of 11

226. Two equal forces (P each) act at a point inclined to each other at an angle of 120°. The magnitude of their resultant is

2P

P/2

P/4

P

227. When the fluid is in-compressible, for which the density is

Change

Constant

Both

None of these

228. A train is moving with a velocity of 25 m/s and a car is moving behind it by a velocity of 8 m/s in same direction. The relative velocity of train with respect to car is

17 m/s

33 m/s

17.5 m/s

None of these

229. Above a certain velocity the fluid flow, the motion of the fluid becomes:

Irregular

B and C

Unsteady

Steady

230. The resultant of two forces, one double the other in magnitude, is perpendicular to the smaller of the two forces. The angle between the two forces is

90°

60°

120°

150°

231. A pendulum bob is suspended inside a lift moving upward with constant velocity. If mass of the bob is 50 g then its weight inside the compartment is

0.05 N

0.5 N

N

Zero

232. If solid sphere and solid cylinder of same mass and density rotate about their own axis, the moment of inertia will be greater for

Solid sphere

Equal both

Solid cylinder

Both

233. The rain drop falling from the sky reach the ground with

Variable speed

Constant terminal velocity

Variable acceleration

Constant acceleration (g)

234. A force of 50 dynes is acted on a body of mass 5 g which is at rest, for an interval of 3 seconds, then impulse is

0.15 x 10¯³ Ns

1.5 x 10¯³ Ns

0.98 x 10¯³ Ns

2.5 x 10¯³ Ns

235. The value of g on the moon whose diameter is ¼ that of earth is 1/6 of that of earth. The ratio of escape velocities at moon and earth’s surface is nearly:

2 : 5

5 : 1

1 : 1

1 : 5

236. The physical quantity which has the dimensional formula M¹T¯³ is

Surface tension

Density

Solar constant

Compressibility

237. Ball pen functions on the principle of

Gravitational force

Surface tension

Viscosity

Boyle’s law

238. If a body starts from rest and travels 120 cm in the 6th second then what is the acceleration?

0.218 m/s²

0.027 m/s²

0.03 m/s²

0.20 m/s²

239. Angular momentum is

A scalar

A vector

Neither A. nor B.

Either A. or B.

240. For a body moving with constant speed in a horizontal circle, which of the following remains constant?

Kinetic energy

Velocity

Centripetal force

Acceleration

241. If a person with a spring balance and a body hanging from it goes up and up in an airplane, then the reading of the weight of the body as indicated by the spring balance, will

Go on decreasing

Go no increasing

Remains the same

First increase and then decrease

242. The percentage errors in the measurement of mass and speed are 3% and 4% respectively. The maximum error in the measurement of kinetic energy is:

11%

9%

8%

10%

243. A particle undergoes uniform circular motion. About which point on the plane of the circle, will the angular momentum of the particle remain conserved?

Outside the circle

On the circumference of the circle

Inside the circle

Center of the circle

244. A container has a small hole in the bottom. Air can go through this hole, but water cannot. This can be best explained by the statement that

Water molecules are larger than molecules in the air

Surface tension of the water prevents it from

Water molecules are smaller than molecules in the air

Water contains hydrogen atoms, air does not

245. The maximum drag force on a falling sphere is 9.8 N, it weight is

Cannot be calculated

4.9 N

1 N

9.8 N

246. Two projectiles are fired from the same point with the same speed at angles of projection 60° and 30° respectively. Which one of the following is true?

Their maximum height will be same

Their landing velocity will be same

Their time of flight will be same

Their range will be same

247. A body is thrown from a height h with speed u, it hits the ground with speed V

The value of V is minimum if the body is thrown horizontally

The value of V is maximum if the body is thrown vertically upwards

The value of V is maximum if the body is thrown vertically downward

The value of V does not depend on the direction of which it is thrown

248. The density of water is 10³ kg/m³. The water pressure on a submarine is 2.0 x 10⁷ N/m². The depth of the submarine below the surface of the water, in meters is approximately

11000 m

300 m

200 m

8000 m

249. Venturi relation is used measure

Speed of liquid flow

Height of the pipe

Density of the liquid

Pressure of the liquid

250. The dimensions of Planck’s constant is equal to that of

Power

Angular momentum

Momentum

Energy

Page 11 of 11

251. If the earth suddenly stops rotating the value of ‘g’ at equator would:

Decrease

Become zero

Remain unchanged

Increase

252. A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle, the motion of the particle takes place in a plane. It follows that

Its kinetic energy is constant

Its moves in straight line

Its acceleration is constant

Its velocity is constant

253. Three vectors satisfy the relation A . B and A . C = 0, then A is parallel to

B . C

B x C

C

B

254. The column of mercury is a mercury barometer is 76 cm high on a certain day when the barometer is vertical. If the barometer is tilted a few degrees, the vertical height of the mercury column, h, is

Still 76 cm

76 cm minus a function of the angle

76 cm minus the angle

76 cm plus the angle

255. The mass of the block is

21,000 g

3000 g

None of these

30001 b

256. When a body moves in a circular path, no work is done by the force since.

There is no net force

There is no displacement

The force is always away from the center

Force and displacement are perpendicular to each other

257. If vectors P, Q and R have magnitude 5, 12 and 13 units and P + Q = R, the angle between Q and R is

cos¯¹ 7/13

cos¯¹ 5/13

cos¯¹12/13

cos¯¹ 5/12

258. The blood flow is ____________ flow at disystolic pressure.

None of these

Laminar

Turbulent

Mixed

259. If the acceleration due to gravity at the earth’s surface is 9.8 m/s² and the mass of the earth is 90 times that of the moon and radius of earth 4 times that of moon, the value of G at the moon’s surface will be:

1.96 m/s²

None of these

9.8 m/s²

4.9 m/s²

260. A light body A and a heavy body B have equal linear momentum. Then the K.E. of the body A

Is equal to that of B

Is zero

Is greater than that of B

Is smaller than that of B

261. Bernoulli’s equation is based upon law of conservation of

Momentum

Energy

None

Mass

262. Fire fighters have a jet attached to the head of their water pipes in order to

Increase the volume of water flowing per second

Increase the mass of water flowing per second

Increase the velocity of water flowing out

Avoid wastage of water

263. A ball is dropped downwards After 1 second another ball is dropped downwards from the same point. What is the distance between them after 3 seconds?

20 m

50 m

25 m

9.8 m

264. The electrical forces are

None

Repulsive

Attractive

Both A and B

265. Two boats rowing close to one another tend to collide. This is due to the

Air velocity between the narrow gap increases

None

Both A and B

Pressure between the narrow gap decreases

266. In deriving Bernoulli’s equation, it is assumed that the fluid is

Incompressible

All of these

In a steady state

Non-viscous

267. The ability of a fluid to resist force is called

Ductility

Elasticity

Stiffness

Strength

268. When a body is moving on a surface, the force of friction is called

Dynamic friction

Limiting friction

Static friction

Rolling friction

269. The work done in taking a particle from the floor to a table depends on

The time taken in this work

The speed of the particle

The height of the table

The actual path taken

Total Questions:	269
Time Allowed:	120 Minutes
Total Marks:	269
How to Attempt Test:	Please choose the right Option in MCQ-type question.
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ECAT Physics Fluid Dynamics Online Test

ECAT Physics Fluid Dynamics Online Test