MCQs From Dynamics From: HC Verma Physics Volume 11. A body of weight w1 is suspended from the ceiling of a room through a chain of weight w, . The ceiling pulls the chain by a force (a) w1 (b) w2 (c) w1 + w2 (d) w1+w2/22. When a horse pulls a cart, the force that helps the horse ...
MCQs From Dynamics From: HC Verma Physics Volume 1
1. A body of weight w1 is suspended from the ceiling of a
room through a chain of weight w, . The ceiling pulls
the chain by a force
(a) w1 (b) w2 (c) w1 + w2 (d) w1+w2/2
2. When a horse pulls a cart, the force that helps the horse
to move forward is the force exerted by
(a) the cart on the horse (b) the ground on the horse
(c) the ground on the cart (d) the horse on the ground.
3. A car accelerates on a horizontal road due to the force
exerted by
(a) the engine of the car (b) the driver of the car
(c) the earth (d) the road.
4. A block of mass m is placed on a smooth inclined plane
of inclination 0 with the horizontal. The force exerted
by the plane on the block has a magnitude
(a) mg (b) mg I cos° (c) mg cosh (d) mg tan0
5. A block of mass m is placed on a smooth wedge of
inclination 0. The whole system is accelerated
horizontally so that the block does not slip on the wedge.
The force exerted by the wedge on the block has a
magnitude
(a) mg (b) mg I cos() (c) mg cos() (d) mg tan0.
6. Neglect the effect of rotation of the earth. Suppose the
earth suddenly stops attracting objects placed near its
surface. A person standing on the surface of the earth
will
(a) fly up
(b) slip along the surface
(c) fly along a tangent to the earth's surface
(d) remain standing.
7. Three rigid rods are joined to form an equilateral triangle
ABC of side 1 m. Three particles carrying charges
20 p.0 each are attached to the vertices of the triangle.
The whole system is at rest in an inertial frame. The
resultant force on the charged particle at A has the
magnitude
(a) zero (b) 3.6 N (c) 3.61/3 N (d) 7.2 N.
8. A force F1 acts on a particle so as to accelerate it from rest to a velocity v. The force F1 is then replaced by F2 which decelerates it to rest. (a) F1 must be equal to F2 (b) F may be equal to 1 F2 (c) F must be unequal to 1 F (d) none of these.9. Two objects A and B are thrown upward simultaneously with the same speed. The mass of A is greater than the mass of B. Suppose the air exerts a constant and equal force of resistance on the two bodies. (a) The two bodies will reach the same height. (b) A will go higher than B. (c) B will go higher than A. (d) Any of the above three may happen depending on the speed with which the objects are thrown.
10. A smooth wedge A is fitted in a chamber hanging from a fixed ceiling near the earth's surface. A block B placed at the top of the wedge takes a time T to slide down the length of the wedge. If the block is placed at the top of the wedge and the cable supporting the chamber is broken at the same instant, the block will (a) take a time longer than T to slide down the wedge (b) take a time shorter than T to slide down the wedge (c) remain at the top of the wedge (d) jump off the wedge.
11. In an imaginary atmosphere, the air exerts a small force F on any particle in the direction of the particle's motion. A particle of mass m projected upward takes a time t1 in reaching the maximum height and t2 in the return journey to the original point. Then (a) t1 < t2 (b) t1 > t2 (c) t1 = t2 (d) the relation between t1 and t2 depends on the mass of the particle.
12. A reference frame attached to the earth (a) is an inertial frame by definition (b) cannot be an inertial frame because the earth is revolving around the sun (c) is an inertial frame because Newton's laws are applicable in this frame (d) cannot be an inertial frame because the earth is rotating about its axis.
1.(c) w1 + w2
2.(b) the ground on the horse
3.(d) the road
4.(c) mg cosθ
5.(b) mg/cosθ
6.(d) remain standing
7.(a) zero
8.(a) F1 must be equal to F2
9.(b) A will go higher than B
10.(c) remain at the top of the wedge
11.(b) t1 > t2
12.(b) cannot be an inertial frame because the earth is
revolving around the sun
And
(d) cannot be an inertial frame because the earth is
rotating about its axis.