ECAT Physics Fluid Dynamics Chapter Online Test

Page 1 of 11

Physics

1. 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

1 cm

2 cm

8 cm

None

2. The angular momentum of a body is conserved if

Torque acting on it is constant

Force acting on it is zero

Force acting on it is constant

Torque acting on it is zero

3. 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

5 J

3430 J

100 J

350 J

4. Wb/m² is equal to

Henry

Tesla

Watt

Dynes

5. Substance which flows easily are

Petrol

Water

All of these

Kerosene oil

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

22.36 km

25.23 km

22.46 km

20 36 km

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

Centripetal force and radius

Linear velocity and angular velocity

Mass and angular velocity

Moment of inertia and angular velocity

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

Is smaller than that of B

Is equal to that of B

Is zero

Is greater than that of B

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

Variable

Zero

Infinite

Maximum

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

Maximum

Infinite

Minimum

Zero

11. Bernoulli’s equation is applicable for

None of these

Laminar flow

Both laminar and turbulent flow

Turbulent flow

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

0.198 x 10¯³

0.295 x 10¯³

0.301 x 10¯³

0.224 x 10¯³

13. 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

P²t²/3m

Pt/2m

P²t²/m

P²t²/2m

14. 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

Water contains hydrogen atoms, air does not

Surface tension of the water prevents it from

Water molecules are smaller than molecules in the air

15. 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?

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

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

Both hit the ground at the same velocity

Both hit the ground at the same speed

16. 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 radian/s²

16 radian/s²

8 m/s²

16 m/s²

17. 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

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

The momentum changes by mv

The kinetic energy changes by mv²

The momentum changes by 2mv

The kinetic energy changes by (1/2)mv²

19. Which of the following quantities is a vector

Density

Temperature

Volume

Displacement

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

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

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

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

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

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

Inside the circle

On the circumference of the circle

Center of the circle

Outside the circle

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

Mass of the body

Linear velocity of the body

Force in linear motion

Linear kinetic energy of the body

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

An electron captured by a proton

A bullet striking a bag of sand

A man jumping onto a moving cart

Striking of two glass balls

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

22 m

6 m

7.8 m

33 m

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

In the backward direction on both the wheels

In the forward direction on both the wheels

In the forward direction on the rear wheel

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

Page 2 of 11

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

All of these

Law of conservation of momentum

Law of conservation of mass

Law of conservation of energy

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

On the train

On himself

Towards the train

Away from the train

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

Static friction

Limiting friction

Rolling friction

Dynamic friction

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

Force

Acceleration

Velocity

None of these

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

40 km/h

36 km/h

80 km/h

50√2 km/h

31. 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)

98.0 m/s

39.2 m/s

19.6 m/s

9.8 m/s

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

Stationary

Moving fast

Moving slowly

Moving

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

4 times

Double

¼ time

Half

34. At high speeds the force is no longer

Simply proportional

Proportional

None of these

No proportion

35. 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

A/v = constant

v/A = constant

Av = constant

36. 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

37. 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

gh

2gh

√2gh

38. 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 = 90°

θ = 60°

θ = 30°

None of these

39. Which of the following quantity is dimensionless?

Power of lens and gas constant

Plank’s constant

None of these

Gravitational constant

40. 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

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

Angular momentum

Mass

Energy

Linear momentum

42. The Bernoulli’s equation is based on the

Law of conservation of energy

All of these

Law of conservation of mass

Law of conservation of momentum

43. Pick out the wrong pair:

Sp. gravity-hygrometer

Pressure-barometer

Charge-coulomb

Temperature-thermometer

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

640 cm

64 m

64 cm

0.064 m

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

Power

Energy

Angular momentum

Momentum

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

Calorie

Electron-volt

Joule

Watt

47. Internal friction of fluid is called

Surface tension

Resistance

Viscosity

Cohesive force

48. The low blood pressure is known as

Low blood pressure

Systolic

Diastolic

None of these

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

Heat up the air which lifts the rocket

Push against the air

Push against the earth

React against the rocket and push it up

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

Remains same

Decreases

Increases

First A and Then B

Page 3 of 11

51. 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%

8%

10%

9%

52. 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?

400 gf

700 gf

500 gf

300 gf

53. The blood vessels are inflated even in

None of these

Relaxed states between heart beat

Working state between heart beat

Occasionally

54. 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

55. 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?

50 m

25 m

9.8 m

20 m

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

Less than unity

Unity or less

Unity or more

Unity

57. The electrical forces are

None

Repulsive

Both A and B

Attractive

58. The term Brownian movement refers to

Irregular motions of small particles suspended in a fluid

The stretching of a body beyond its elastic limit

Convection currents in a gas but not in a liquid

Convection currents in a liquid or gas

59. Venturi relation is used measure

Speed of liquid flow

Pressure of the liquid

Density of the liquid

Height of the pipe

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

Bernoulli’s equation

None of these

Venturi relation

Torricelli’s theorem

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

π/4

π/2

π

π/3

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

Large

Small

None of these

Very large

63. 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

200

2000

20,000

20

64. 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?

4 m/s

1 m/s

2 m/s

8 m/s

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

All of these

Honey

Thick tar

Mobile oil

66. The blood pressure of the person

Remains the same

Decreases with age

Increases with age

None

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

¼ times

Double

Half

4 times

68. 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

0.5 N

0.05 N

N

Zero

69. Dot product of two mutual perpendicular vector is:

0

None of these

1

∞

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

None of these

Center of mass changes but center of gravity is always same

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

They are always at the same point

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

None of these

1 m/s

4 m/s

2 m/s

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

98 J

968 J

None of these

1980 J

73. Which of the following is the smallest unit?

Angstrom

Meter

Millimeter

Fermi

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

Both will reach simultaneously

Depends on their mass

The slower one

The faster one

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

Its acceleration is also doubled

Its potential energy is also doubled

Its momentum is also doubled

Its kinetic energy is also doubled

Page 4 of 11

76. Length cannot be measured by

Light year

Micron

Fermi

Debye

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

Decrease for both

Decrease for liquids and increase for gases

Increase for liquids and decreases for gases

Increases for both

78. 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

50 cm/s

5 cm/s

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

Weight in the liquid

Weight in air

Density

Weight in water

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

1 and 2

2 and 3

4 and 5

3 and 4

81. Angular momentum has the same unit as

Work x frequency

Power x time

Linear momentum x time

Impulse x distance

82. Ball pen functions on the principle of

Surface tension

Viscosity

Gravitational force

Boyle’s law

83. 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

E/2

F/√2

Zero

84. S.I unit of magnetic flux is

Weber

Weber per metre

Weber metre¯²

Weber per metre⁴

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

None of these

Remains unchanged

Increases

Decreases

86. A chimney works best when it is

Exposed to air currents

Tall

A and B

Not tall but wide

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

Variable speed and constant velocity

Constant acceleration

Variable acceleration

Constant retardation

88. Identify the pair whose dimensions are equal

Torque and work

Force and work

Force and stress

Stress and energy

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

Decreases

Doubles

Increases

Does not change

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

All of these

Centrifugal force

Centripetal force

Gravitational force

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

Laminar

Turbulent

Mixed

None of these

92. At terminal velocity, fluid friction is

Maximum

Zero

Minimum

None of these

93. 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:

40°

50°

45°

60°

94. 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

P/4

95. 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

T₁ > T₂

T₁ = T₂

T₂ > T₁

Tension in the string always remains the same

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

M(g + a)

Mg

0

M(g – a)

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

Force and displacement are perpendicular to each other

The force is always away from the center

There is no displacement

There is no net force

98. 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¯¹12/13

cos¯¹ 7/13

cos¯¹ 5/12

cos¯¹ 5/13

99. 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

2 ms¯²

10 ms¯²

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

Angular velocity

Axis of rotation

Mass distribution

Mass of object

Page 5 of 11

101. 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

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

Become zero

Decrease

Increase

Remain unchanged

103. The direction of the angular velocity vector is along

The axis of rotation

The outward radius

The tangent to the circular path

The inward radius

104. An instrument called a sphygmomanometer measure

Density of water

Blood pressure

Milk density

None of these

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

Both have the same momentum

Light object

Data is not sufficient

Heavy object

106. The concentration of red blood cells in blood is

~ 30%

– 45%

~ 50%

– 40%

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

None of these

Car will cover less distance before rest

Both will cover equal distance

Truck will cover less distance before rest

108. 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

2W

Zero

W

W/2

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

Magnus effect

Bernoulli’s equation

Surface energy

Equation of continuity

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

Final velocity

Initial velocity

Instantaneous velocity

Terminal velocity

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

Momentum

Mass

Energy

All

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

Variable acceleration

Variable speed

Constant terminal velocity

Constant acceleration (g)

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

Non-viscous

All of these

In a steady state

Incompressible

114. 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

7,200 N

100,000 N

3,600 N

10,000 N

115. 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.

90°

60°

120°

None of these

116. 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

Roughly equal

Exactly equal

Zero

Unequal

117. 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

76 cm plus the angle

Still 76 cm

76 cm minus the angle

76 cm minus a function of the angle

118. A flowing liquid possesses

All

P.E.

K.E.

Pressure Energy

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

Equal both

Both

Solid cylinder

Solid sphere

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

Slide upon each other

None of these

Stick to each other

Roll upon each other

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

Elasticity

Stiffness

Ductility

Strength

122. 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

36000

129600

360000

72000

123. 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

4 times

¼ times

½ of 4 cm diameter pipe

Twice

124. 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

1 : 5

5 : 1

1 : 1

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

Volume of fluid

Flow rate

Mass of fluid

Density of fluid

Page 6 of 11

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

None of these

Action of gravity

h₁ – h₂

(h₁ – h₂) and falling under gravity

127. 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

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

Energy

Fluid

Mass

Momentum

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

300 m

100 m

200 m

400 m

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

Tangential

Centrifugal

Radial

Centripetal

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

The blood pressure increase at high altitudes

The density of blood decreases at high altitudes

The percentage of oxygen in the air increase

The atmospheric pressure decreases there

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

High

Low

Zero

Constant

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

1 mm/s

1 μm/s

1 cm/s

1 nm/s

134. 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

1.3

2.3

1.5

3.0

135. Which of the following is true?

Neither momentum nor kinetic energy is conserved in inelastic collisions

Momentum is conserved in all collisions but not kinetic energy

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

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

None of these

Moves in different direction

Slowly moves in one direction

Moves along the same path as

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

90°

0°

60°

120°

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

Energy and Young’s modulus

Light year and time

Torque and work

Angular momentum and work

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

Infinite

Equal to what is in turbulent flow

Maximum

Minimum

140. 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

0.98 x 10¯³ Ns

2.5 x 10¯³ Ns

0.15 x 10¯³ Ns

1.5 x 10¯³ Ns

141. With the increase of temperature viscosity

Decrease

Increase

Remains same

Doubles

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

None

Mass

Momentum

Energy

143. 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)

Zero

0.5 kg wt

1.0 kg wt

2.0 kg wt

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

Not conserved

Conserved

Somewhat conserved

None of these

145. 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

3.2 joule

2.8 joule

3.8 joule

4.4 joule

146. 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

200 m

300 m

8000 m

147. Surface tension of water is reduced by adding

Plastic

Camphor

Detergents

Both A and B

148. 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

5 N

12 N

2 N

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

Compressibility

Density

Surface tension

Solar constant

150. Coefficient of viscosity of honey is greater than

Milk

Petrol

Water

Alcohol

Page 7 of 11

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

Fv²

F/v

v/F

Fv

152. Numerical value of magnitude of a physical quantity is

Inversely proportional to magnitude of the unit

Directly proportional to magnitude of the unit

Independent of system of units

Either (B) or (C)

153. Reason of weightlessness in a satellite is

None of these

Zero gravity

Center of mass

Zero reaction force by satellite surface

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

Momentum decreases

Kinetic energy decreases

Kinetic energy increases

Momentum increases

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

Momentum

Mass

Angular momentum

Kinetic energy

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

None

Air velocity between the narrow gap increases

Pressure between the narrow gap decreases

Both A and B

157. Angular momentum is

A vector

Either A. or B.

Neither A. nor B.

A scalar

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

1 N

9.8 N

Cannot be calculated

4.9 N

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

Thrice the initial value

Four times the initial value

Twice the initial value

Same as the initial value

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

Change in KE is zero

Momentum change is mvr

Change in KE is mv²

Change in KE is ½ mv²

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

R²

(1/R)²

1/R

R

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

Are equal to each other

Cannot be predicted

Are equal to each other in magnitude

Are not equal to each other in magnitude

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

All

Non-ideal fluid

Ideal fluid

Prefect fluid

164. 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:

None of these

9.8 m/s²

4.9 m/s²

1.96 m/s²

165. When fluid is incompressible then

Flow of the fluid is straight line

Density of the fluid is constant

Volume of the fluid is constant

Velocity of the fluid is constant

166. A jet engine works on the principle of

Conservation of energy

Conservation of linear momentum

Conservation of mass

Conservation of angular momentum

167. The low blood pressure is

70 – 80 torr

78 – 809 torr

75 – 80 torr

79 – 80 torr

168. The unit of focal power of a lens is

Watt

Kilo watt

Diopter

Horse power

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

None of these

Linear momentum

Linear impulse

Force

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

Zero

Remains same

Decreases

Increases

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

Electric flux

Magnetic flux

Mass flux

Both a and b

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

M⁰L⁰T²

ML⁰T⁰

MLT⁰

M⁰LT²

173. Surface area is

Both scalar and vector

Neither scalar nor vector

Vector

Scalar

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

Moment of inertia decreases

Angular momentum increases

Moment of inertia increases

Angular momentum decreases

175. Velocity of fluid increases where the pressure is

Low

High

Changes continuously

Constant

Page 8 of 11

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

2 x 10⁵ s

2 x 10⁶ s

1 x 10⁵ s

1 x 10⁶ s

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

Thrice

Twice

Four times

Once

178. 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

None of these

17.5 m/s

17 m/s

33 m/s

179. 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 h

Proportional to h²

Independent of h

Proportional to h¹⁄ ²

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

Sound heard

High flow speed

Initially turbulent

All of these

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

Decreases

Zero

Remains same

Increases

182. 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

3 s

7 s

9 s

5 s

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

Decreases rapidly

Decreases

None of these

Increases

184. The mass of the block is

30001 b

3000 g

21,000 g

None of these

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

Av = constant

A/v = constant

v/A = constant

None of these

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

Laminar flow

Turbulent flow

Both a and b

None of these

187. Drag force is given by

Pascal’s law

Newton’s law

Stokes law

Gauss law

188. 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

Zero

½ Mg

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

The blood pressure increase at high altitudes

The percentage of oxygen in the air increase

The atmospheric pressure decreases there

The density of blood decreases at high altitudes

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

Mg/2

More than mg

Mg

More than 2mg

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

8 times

6 times

4 times

2 times

192. A flowing liquid possesses

Pressure Energy

P.E.

All

K.E.

193. 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

Momentum

Kinetic energy

Velocity

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

Constant terminal velocity

Variable acceleration

Constant acceleration (g)

Variable speed

195. 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?

0.1 m/s

1 m/s

10 m/s

0.01 m/s

196. Force of friction is present in

All of these

Liquid

Gases

Solid

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

Surface tension of the gas

Cohesion between the gas molecules and the container

Adhesion between the gas molecules and the container

Collision between the gas molecules and the container

198. V = √2g(h₁ – h₂) shows the

Bernoulli’s theorem

None of these

Equation of continuity

Torricelli’s theorem

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

When net external force is acting upon the system

None of these

When a net external impulse is acting upon the system

When a net eternal torque is acting upon the system

200. Stoke’s law is applicable to

Motion through horizontal surface

Motion through free space

Motion through non-resistive medium

Motion through viscous medium

Page 9 of 11

201. Unite of impulse in

Newton

Kg m

Joule

Kg m/s

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

R

(3/2)R

4R

2R

203. 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 be just floating at the same point in space

It will lose its velocity gradually

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

6.29 x 10¯³

6.12 x 10¯³

6.18 x 10¯³

6.49 x 10¯³

205. The high blood pressure is

130 torr

100 torr

110 torr

120 torr

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

An α particle

An electron

A proton

A deuteron

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

2

1

4

3

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

1 : 4 : 9

None of these

1 : 2 : 3

1 : 3 : 5

209. The rectangular components of force 5 dyne are

3 and 4 dyne

2.5 and 25 dyne

1 and 2 dyne

2 and 3 dyne

210. The atmosphere is held to the earth by

Clouds

The rotation of earth

Gravity

Winds

211. 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

It moves in a circular path

None of these

Linear momentum is constant

Velocity is constant

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

tan¯¹(-P/Q)

sin¯¹(P/Q)

tan¯¹(P/Q)

cos¯¹(-P/Q)

213. The unit of inductance is equivalent to

Volt/ampere x second

Volt x second/ampere

Volt x ampere/second

Ampere/volt x second

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

More than 4 dynes

Between 1 and 7 dyne

Between 3 and 4 dyne

More than 3 dynes

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

Perpendicular to each other

Antiparallel to each other

Parallel to each other

Inclined to each other at an angle of 45°

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

Equal to weight of liquid displaced

Less than the weight of liquid displaced

Weight of body-weight of liquid displaced

Zero

217. Which of these statements is not correct?

Moment of inertia does not depend on mass of body

Moment of inertia depends on choice of axes

None of these

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

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

Linear momentum

Work

Angular momentum

Energy

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

Increases

Decreases

First increases, then decreases

Remains same

220. 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 east to west

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

To fall vertically down

To fall at an angle going from west to east

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

The horse on the ground

The ground on the cart

The horse on the cart

The ground on the horse

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

1 : 3

1 : 1

3 : 1

2 : 1

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

Change

Both

Constant

None of these

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

3 J

2 J

1 J

4 J

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

Increase the mass of water flowing per second

Avoid wastage of water

Increase the velocity of water flowing out

Increase the volume of water flowing per second

Page 10 of 11

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

By running on the plane

By jumping

By rolling your body on the surface

By spitting or sneezing

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

4.5 x 10¯¹⁰ J

4.5 x 10¯¹⁹ J

3 x 10¯¹⁹ J

3 x 10¯¹⁰ J

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

Angular acceleration

None of these

No acceleration

Linear acceleration

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

Become four times, its initial value

Become three times, its initial value

Become twice its initial value

Remains constant

230. 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

42 km/h

10 km/h

40 km/h

37.5 km/h

231. 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

2 x 10² cm³

1 x 10² cm³

1.763 x 10² cm³

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

Terminal velocity

Instantaneous velocity

Final velocity

Initial velocity

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

The acceleration of the object is zero

The object is moving at constant speed

The object must be at rest

The object can be at rest

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

60 N

21 N

15 N

30 N

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

Irregular

B and C

Steady

Unsteady

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

Square

Circular

Rough

Spherical

237. 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)

14.7 m

9.8 m

19.6 m

4.9 m

238. 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 acceleration is constant

Its kinetic energy is constant

Its moves in straight line

Its velocity is constant

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

0.521 x 10¯³

0.599 x 10¯³

0.564 x 10¯³

0.594 x 10¯³

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

0.03 m/s²

0.20 m/s²

0.027 m/s²

0.218 m/s²

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

Increase

None of these

Decreases

Zero

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

The drive of the car

Force by steering wheel

Friction due to tyres

Force of brakes

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

Force, impulse

Pressure, stress

Velocity, speed

Work, energy

244. 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

.gh

2gh

√gh

245. 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

13 N, 5 N

16 N, 2 N

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

High

Zero

Low

Constant

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

Attractive

Both A and B

Repulsive

None

248. Blood has a density

Lesser then water

None of these

Greater then water

Equal to water

249. 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 = 4t₂

t₁ = t₂/2

t₁ = t₂

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

Momentum

Mass

Kinetic energy

Speed

Page 11 of 11

251. The Systolic blood pressure comes when

None of these

Vessel collapse

Cutting off the blood flow

All of these

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

1 : 1

1 : 4

4 : 1

1 : 2

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

Surface tension effect

Air currents of the earth atmosphere

Up thrust of air

Viscous force exerted by air

254. Swimming is based on the principle of

Newton’s 2nd law

Newton’s 1st law

Newton’s 3rd law

All

255. 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 range will be same

Their time of flight will be same

Their landing velocity will be same

Their maximum height will be same

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

B

B x C

C

B . C

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

The ball had covered more than half the distance

The ball had covered exactly half the distance

The ball had covered less than half the distance

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

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

1.000 x 10¯³

1.012 x 10¯³

1.014 x 10¯³

0.954 x 10¯³

259. 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

0.98 m

Full length of the capillary tube

0.1 m

0.2 m

260. Angular momentum is

Polar vector

Axial vector

Scalar

At 45° angle

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

The actual path taken

The time taken in this work

The speed of the particle

The height of the table

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

Size of the body

Diameter of the body

Radius of the body

Square of the diameter of the body

263. 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

4 N

20 N

8 N

264. 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

16

14

13

18

265. 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

60°

90°

150°

120°

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

55%

77%

44%

66%

267. In a uniform circular motion

Only velocity change, acceleration remain constant

Kinetic energy remain constant

Speed and acceleration change

Velocity and acceleration remain constant

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

1500 m

1400 m

1300 m

1200 m

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

Acceleration

Velocity

Centripetal force

Kinetic energy

Total Questions:	269
Time Allowed:	120 Minutes
Total Marks:	269
How to Attempt Test:	Please choose the right Option in MCQ-type question.
Test Helpful For:	ECAT Entry Test Physics Online Test Interview Questions about Physics All Universities Entrance Test Recruitments Tests

ECAT Physics Fluid Dynamics Online Test

ECAT Physics Fluid Dynamics Online Test