ECAT Physics Fluid Dynamics Online Test

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

2. 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

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

4. The high blood pressure is

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

6. 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

7. 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:

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

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

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

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

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

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

14. 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

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

16. 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

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

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

19. 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

20. 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:

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

22. Which of the following is true?

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

24. 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?

25. 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?

26. V = √2g(h₁ – h₂) shows the

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

28. Identify the pair whose dimensions are equal

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

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

31. 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

32. Blood has a density

33. 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

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

35. 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?

36. 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

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

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

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

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

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

 

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

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

44. Drag force is given by

45. Pick out the wrong pair:

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

47. 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

48. 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

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

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

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

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

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

54. 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

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

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

57. 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

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

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

60. 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

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

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

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

64. Angular momentum is

65. Angular momentum is

66. The angular momentum of a body is conserved if

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

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

69. Surface area is

70. 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

71. 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

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

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

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

75. The Bernoulli’s equation is based on the

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

77. 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

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

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

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

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

82. 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

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

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

85. 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

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

87. 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

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

89. 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)

90. Force of friction is present in

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

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

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

94. Which of the following quantity is dimensionless?

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

96. 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

97. 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

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

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

100. Wb/m² is equal to

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

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

103. 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)

104. 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

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

106. The unit of inductance is equivalent to

107. Surface tension of water is reduced by adding

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

109. When fluid is incompressible then

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

111. 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)

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

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

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

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

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

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

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

119. 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

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

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

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

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

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

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

126. Dot product of two mutual perpendicular vector is:

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

128. 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?

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

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

131. Unite of impulse in

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

133. The blood vessels are inflated even in

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

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

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

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

138. With the increase of temperature viscosity

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

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

141. A chimney works best when it is

142. Bernoulli’s equation is applicable for

143. Angular momentum has the same unit as

144. The low blood pressure is known as

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

146. 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

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

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

149. At high speeds the force is no longer

150. Which of these statements is not correct?

151. 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:

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

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

154. 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

155. The mass of the block is

156. The unit of focal power of a lens is

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

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

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

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

161. 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

162. The electrical forces are

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

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

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

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

167. Velocity of fluid increases where the pressure is

168. 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

169. An instrument called a sphygmomanometer measure

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

171. The rectangular components of force 5 dyne are

172. S.I unit of magnetic flux is

173. 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

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

175. 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:

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

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

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

179. The low blood pressure is

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

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

182. 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

183. The atmosphere is held to the earth by

184. 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

185. Numerical value of magnitude of a physical quantity is

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

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

188. 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.

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

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

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

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

193. 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

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

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

196. Reason of weightlessness in a satellite is

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

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

199. Substance which flows easily are

200. 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?

201. 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

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

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

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

205. 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

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

207. The term Brownian movement refers to

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

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

210. A flowing liquid possesses

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

212. Swimming is based on the principle of

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

214. Length cannot be measured by

215. 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?

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

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

218. 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.

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

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

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

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

223. 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

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

225. In a uniform circular motion

226. 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.

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

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

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

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

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

232. The concentration of red blood cells in blood is

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

234. 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:

235. Which of the following is the smallest unit?

236. The direction of the angular velocity vector is along

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

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

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

240. Venturi relation is used measure

241. A jet engine works on the principle of

242. At terminal velocity, fluid friction is

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

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

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

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

247. Internal friction of fluid is called

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

249. The blood pressure of the person

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

251. Ball pen functions on the principle of

252. 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:

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

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

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

256. Coefficient of viscosity of honey is greater than

257. A flowing liquid possesses

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

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

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

261. 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

262. Stoke’s law is applicable to

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

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

265. The Systolic blood pressure comes when

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

267. 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

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

269. Which of the following quantities is a vector