Saturday, 22 February 2020

PLUS ONE PHYSICS QUESTIONS AND ANSWERS

Chapter 6
             WORK, ENERGYAND POWER

1. Which of the following is a non conservative force

a. Viscous force
b. Gravitation force
c. Electric force
d. Nuclear force

Ans:-  viscous force

2. The Newton's metr is the unit of

Ans:- work

3.  The work done  by Earth's  gravitational force  in keeping the moon in its circular orbit  is an

Ans:- zero

4.  What is the unit of energy

Ans:- kWh

5. A bullet of mass m is  fried with a velocity v into a block  of wood of mass M initially at rest The velocity after collision is

Ans:- m/m+M ×v

6. During elastic collision between two bodies kinetic energy alone is conserved . State whether this statement true or False

Ans:- False,  during elastic collision between two bodies  both momentum and kinetic energy are conserved

7. When conservative force does positive work on abody .the potential energy of the body
Ans:- decreases

8. Two masses of 2g and 8 g are moving with equal kinetic energy .The ratio of their momenta is

Ans:-  1: 2

9. The work done by the conservatives force is negative  then the potential energy  of the body decreases . State whether statement is true or False

Ans:- False. The potential energy of the  body increases

10.  Energy is lost due to friction force , is the statement currect in terms of physics. Explain?
Ans:- No energy is never lost  but get converted into  other forms

11.  State the law of conservation energy

Ans:- Energy can nighter be created nor be destroyed . It can be converted into one form to another

12. State the true or False " a block is sliding down  an inclined plan work done  by functional force is zero

Ans:-  False,  A block is sliding  down  on inclined plane  work done by the frictional force is negative because force and displacement are opposite direction

13. Difine elastic collision

Ans:- initial kinetic energy is equal to  the final kinetic energy .The collision in which both  kinetic energy and linear momentum of the colliding  bodies remain conserved  is called elastic collision

14.  What is the unit of spring constant

Ans:-  Nm -1

15. Spring force  is conservative  force.  Explain?

Ans:- work done  depends only an initial  and final  positions work done  is zero.

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