McqMate
| 201. |
A ladder is resting on a smooth ground and leaning against a rough vertical wall. The force of friction will act |
| A. | towards the wall at its upper and |
| B. | away from the wall at its upper end |
| C. | downward at its upper end |
| D. | upward at its upper end |
| Answer» D. upward at its upper end | |
| 202. |
The forces which do not meet at one point and their lines of action do not lie on the same plane are known as |
| A. | coplaner concurrent forces |
| B. | coplaner non-concurrent forces |
| C. | non-coplaner concurrent forces |
| D. | none of these |
| Answer» D. none of these | |
| 203. |
The linear acceleration (a) of a body rotating along a circular path of radius (r) with an angular acceleration of ? rad / s2, is |
| A. | a = ? / r |
| B. | a = ?.r |
| C. | a = r / ? |
| D. | none of these |
| Answer» B. a = ?.r | |
| 204. |
The velocity ratio in case of an inclined plane inclined at angle ? to the horizontal and weight being pulled up the inclined plane by vertical effort is |
| A. | sin ? |
| B. | cos ? |
| C. | tan ? |
| D. | cosec ? |
| Answer» A. sin ? | |
| 205. |
A body of mass m moving with a constant velocity v strikes another body of same mass m moving with same velocity but in opposite direction. The common velocity of both the bodies after collision is |
| A. | v |
| B. | 2 v |
| C. | 4 v |
| D. | 8 v |
| Answer» B. 2 v | |
| 206. |
When a body of mass m attains a velocity v from rest in time t, then the kinetic energy of translation is |
| A. | mv2 |
| B. | mgv2 |
| C. | 0.5 mv2 |
| D. | 0.5 mgv2 |
| Answer» C. 0.5 mv2 | |
| 207. |
Whenever a force acts on a body and the body undergoes a displacement, then |
| A. | work is said to be done |
| B. | power is being transmitted |
| C. | body has kinetic energy of translation |
| D. | none of these |
| Answer» A. work is said to be done | |
| 208. |
The maximum displacement of a body, from its mean position is called amplitude. |
| A. | Right |
| B. | Wrong |
| Answer» A. Right | |
| 209. |
The unit of power in S.I. units is |
| A. | horsepower |
| B. | joule |
| C. | watt |
| D. | kg-m |
| Answer» C. watt | |
| 210. |
The moment of inertia of a solid cylinder of mass m, radius r and length l about the longitudenal axis or polar axis is |
| A. | mr2 / 2 |
| B. | mr2 / 4 |
| C. | mr2 / 6 |
| D. | mr2 / 8 |
| Answer» A. mr2 / 2 | |
| 211. |
When the spring of a watch is wound, it will possess |
| A. | strain energy |
| B. | kinetic energy |
| C. | heat energy |
| D. | electrical energy |
| Answer» A. strain energy | |
| 212. |
The path of the projectile is a parabola. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 213. |
The wheels of a moving car possess |
| A. | potential energy only |
| B. | kinetic energy of translation only |
| C. | kinetic energy of rotation only |
| D. | kinetic energy of translation and rotation both |
| Answer» D. kinetic energy of translation and rotation both | |
| 214. |
Frequency of vibrations means the number of cycles per second. |
| A. | Yes |
| B. | No |
| Answer» A. Yes | |
| 215. |
A resultant force is a single force which produces the same effect as produced by all the given forces acting on a body |
| A. | TRUE |
| B. | FALSE |
| Answer» A. TRUE | |
| 216. |
The maximum mechanical advantage of a lifting machine is |
| A. | 1 + m |
| B. | 1 - m |
| C. | 1 / m |
| D. | m |
| Answer» C. 1 / m | |
| 217. |
In a wormed geared pully block, if the number of teeth one the worm wheel is doubled, then its velocity ratio is also doubled. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 218. |
The moment of inertia of a thin rod of mass m and length l, about an axis through its centre of gravity and perpendicular to its length is |
| A. | ml2 / 4 |
| B. | ml2 / 6 |
| C. | ml2 / 8 |
| D. | ml2 / 12 |
| Answer» D. ml2 / 12 | |
| 219. |
Coplaner non-concurrent forces are those forces which |
| A. | meet |
| B. | do not meet |
| Answer» B. do not meet | |
| 220. |
The linear velocity of a body rotating at ? rad / s along a circular path of radius r is given by |
| A. | ? / r |
| B. | ?.r |
| C. | ?2/r |
| D. | ?2.r |
| Answer» B. ?.r | |
| 221. |
The acceleration of a particle moving with simple harmonic motion is |
| A. | zero |
| B. | minimum |
| C. | maximum |
| Answer» A. zero | |
| 222. |
When a train is rounding a curve, the side thrust on the wheel flanges is prevented by raising the outer edge of the rail. |
| A. | Yes |
| B. | No |
| Answer» A. Yes | |
| 223. |
In collision of elastic bodies, the coefficient of restitution is the ratio of the relative velocity after impact to the relative velocity before impact. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 224. |
The rate of change of displacement of a body is called |
| A. | velocity |
| B. | acceleration |
| C. | momentum |
| D. | none of these |
| Answer» A. velocity | |
| 225. |
The maximum frictional force, which comes into play, when a body just begins to slide over the surface of the other body, is known as |
| A. | static friction |
| B. | dynamic friction |
| C. | limiting friction |
| D. | coefficient of friction |
| Answer» C. limiting friction | |
| 226. |
The negative acceleration is called retardation. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 227. |
The velocity ratio for the second system of pulleys is n. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 228. |
The angle between two forces when the resultant is maximum and minimum respectively are |
| A. | 0? and 180? |
| B. | 180? and 0? |
| C. | 90? and 180? |
| D. | 90? and 0? |
| Answer» A. 0? and 180? | |
| 229. |
The angular velocity (in rad / s) of a body rotating at N revolutions per minute is |
| A. | ? N / 60 |
| B. | ? N / 180 |
| C. | 2? N / 60 |
| D. | 2? N/180 |
| Answer» C. 2? N / 60 | |
| 230. |
If P is the force acting on the body, m is the mass of the body and a is the acceleration of the body, then according to Newton's second law of motion, |
| A. | P + m.a = 0 |
| B. | P - m.a = 0 |
| C. | P x m.a = 0 |
| D. | P/m.a = 0 |
| Answer» B. P - m.a = 0 | |
| 231. |
Coplaner concurrent forces are those forces which |
| A. | meet at one point, but their lines of action do not lie on the same plane |
| B. | do not meet at one point and their lines of action do not lie on the same plane |
| C. | meet at one point and their lines of action also lie on the same plane |
| D. | do not meet at one point, but their lines of action lie on the same plane |
| Answer» C. meet at one point and their lines of action also lie on the same plane | |
| 232. |
The time of flight of a projectile on downward inclined plane depends upon |
| A. | angle of projection |
| B. | angle of inclination of the plane |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» C. both (a) and (b) | |
| 233. |
Concurrent forces are those forces whose lines of action |
| A. | lie on the same line |
| B. | meet at one point |
| C. | meet on the same plane |
| D. | none of these |
| Answer» B. meet at one point | |
| 234. |
During elastic impact, the relative velocity of the two bodies after impact is |
| A. | equal to |
| B. | equal and opposite to |
| C. | less than |
| D. | greater than |
| Answer» B. equal and opposite to | |
| 235. |
Coefficient of friction depends upon |
| A. | area of contact only |
| B. | nature of surface only |
| C. | both (a) and (b) |
| D. | none of these |
| Answer» B. nature of surface only | |
| 236. |
Work done is said to be zero, when |
| A. | some force acts on a body, but displacement is zero |
| B. | no force acts on a body but some displacement takes place |
| C. | either (a) or (b) |
| D. | none of the above |
| Answer» C. either (a) or (b) | |
| 237. |
The moment of inertia of a square of side (a) about an axis through its centre of gravity is |
| A. | a4/4 |
| B. | a4/8 |
| C. | a4/12 |
| D. | a4/36 |
| Answer» C. a4/12 | |
| 238. |
When a particle moves along a straight path, there will be centripetal acceleration as well as tangential acceleration. |
| A. | Right |
| B. | Wrong |
| Answer» B. Wrong | |
| 239. |
The motion of the body from one extremity to the other is known as a beat. |
| A. | Agree |
| B. | Disagree |
| Answer» A. Agree | |
| 240. |
The force which acts along the radius of a circle and directed towards the centre of the circle is known as centripetal force. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 241. |
The centre of gravity of a quadrant of a circle lies along its central radius (r) at a distance of |
| A. | 0.5 r |
| B. | 0.6 r |
| C. | 0.7 r |
| D. | 0.8 r |
| Answer» B. 0.6 r | |
| 242. |
A body is said to move or vibrate with simple harmonic motion if its acceleration is directed towards the mean position. |
| A. | True |
| B. | False |
| Answer» A. True | |
| 243. |
The unit of energy in S.I. units is |
| A. | dyne |
| B. | watt |
| C. | kg - m |
| D. | joule |
| Answer» D. joule | |
| 244. |
The slope on the road surface generally provided on the curves is known as |
| A. | angle of friction |
| B. | angle of repose |
| C. | angle of banking |
| D. | none of these |
| Answer» C. angle of banking | |
| 245. |
Two balls of equal mass and of perfectly elastic material are lying on the floor. One of the ball with velocity v is made to struck the second ball. Both the balls after impact will move with a velocity |
| A. | v |
| B. | v / 2 |
| C. | v / 4 |
| D. | v / 8 |
| Answer» B. v / 2 | |
| 246. |
According to the law of moments, if a number of coplaner forces acting on a particle are in equilibrium, then |
| A. | their algebraic sum is zero |
| B. | their lines of action are at equal distances |
| C. | the algebraic sum of their moments about any point in their plane is zero |
| D. | the algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point |
| Answer» C. the algebraic sum of their moments about any point in their plane is zero | |
| 247. |
A force while acting on a body may |
| A. | change its motion |
| B. | balance the forces, already acting on it |
| C. | give rise to the internal stresses in it |
| D. | all of these |
| Answer» D. all of these | |
| 248. |
For a self locking machine, the efficiency must be |
| A. | equal to 50% |
| B. | less than 50% |
| C. | greater than 50% |
| D. | 100% |
| Answer» B. less than 50% | |
| 249. |
The maximum acceleration of a particle moving with simple harmonic motion is |
| A. | ? |
| B. | ?r |
| C. | ?2r |
| D. | ?/r |
| Answer» C. ?2r | |
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