**Multiple choice question with one or more answer**

1. Which of these is true of a conservative force?

a. Workdone between two points is independent of the path

b. Workdone in a closed loop is zero

c. if the workdone by the conservative is positive,its potential energy increases

d. None of the these

2.A particle is acted upon by a force of costant magnitude which is always perpendicular to the velocity of the particle.The motion of the particle takes place in a plane.it follows that

a. velocity is constant

b. accelerattion is constant

c. KE is constant

d. Particle moves in a circular path

3. A package is dropped out of airplane in a level flight.If air resistance could be neglected.which of these is true

a. Package will follow a parabolic path with respect to a observer on the groud

b Package will follow a vertically straight line path with respect to the observer in the plane.

c.Package will follow a vertically straight line path with respect to a observer on the groud

b Package will follow a parabolic path with respect to the observer in the plane.

4.A small mass m is suspended from one end of a vertical string. and then whirled in a horizontal circle at a constant speed v.

Which of the followings is true

a.The strings stays vertical

b.The string becomes inclined to the vertical.

c.There is no force on mass m except its weight

d.The angle of inclination of the string does not depend on the v

e.The centripetal force on m is mg

5.A IITJEE text book of mass M rests flat on a horizontal table of mass m placed on the ground.Let R

_{X->Y}be the constant force exerted by the body x on body Y.Which of the following is true for the forces R

_{ground->table}and R

_{table->ground}

a. It is action and reaction pair

b. have equal magnitude

c. Opposite direction

d.have resultant zero

6.The tension in cable supporting an elevator is equal to th weight of the elevetor.The elevator may be

a. going up with incresing speed

b. going down with increasing speed

c. going up with uniform speed

d. going down with uniform speed.

7 A simple pendulum consists of a mass attached to a light string l. if the system is oscillating through small angles which of the following is true

a.The freqiency is independent of the acceleration due to gravity g

b.The period depends on the amplitude of the ocsillation

c.the period is independent of mass m

d. the period is independent of lenght l

8.A ball is thrown into the air with an intial speed u.The time interval taken for the ball to rise to its maximum height is t

_{1}.The time interval taken for the ball to fall back from this maximum height is t

_{2}.Under real life condition,which of the following is satisfied

a.t

_{2}> t

_{2}

b t

_{2}< t

_{2}

c. t

_{2}=t

_{2}

d. t

_{1}> t

_{2}if u is great enough

9. Let v and a denote the velolcity and acceleratio respectivly of the particle in one dimension motion.

a.the speed of the particle decreases when

**v**.

**a**<0

b. the speed of the particle decreases when

**v**.

**a**>0

c.the speed of the particle increases when

**v**.

**a**=0

d. the speed of the particle decreases when |

**v**|<|

**a**|

10. A refrence frame attached to the earth

a.is an inertial frame by defination

b.cannot be inertial frame as earth is resolving around the sun

c.is an intertial frame because Newton's law are applicable in this frame

d.cannot be intertial frame because earth is rotating about its own axis

**Solutions**

1.a,b

2.c,d

3.a,b

4. b

5. a,b,c,d

6. c,d

7. c

8 a

9 a

10 b,d