Work and Energy Test

Result

Work and Energy Test - 14

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

When an electric fan is switched on, most of the electrical energy supplied to it gets converted into

A
light energy

B
chemical energy

C
heat energy

D
mechanical energy

Solution

When an electric fan is switched on, its blades start rotating. These blades possess kinetic energy, which is a form of mechanical energy. Heat energy is also generated in this process, though it is much less as compared to the mechanical energy generated.

The correct answer is D.

Why alternative A is wrong:

A rotating electric fan does not produce light. It forces the air around it to move.

Why alternative B is wrong:

There is no chemical reaction during the movement of electric fans.

Why alternative C is wrong:

A small amount of heat energy is generated during the rotation of an electric fan; but the maximum amount of energy is converted into mechanical energy.
Question 2
1 / -0

Use the following information to answer the next question.

Pamela is learning to play billiards. She hits the black ball with a cue stick; the ball starts moving and hits a stationary white ball, which then rolls into a pocket.

The stationary white ball started rolling because

A
heat energy from the black ball was transferred to it

B
kinetic energy from the black ball was transferred to it

C
potential energy from the black ball was transferred to it

D
gravitational energy from the black ball was transferred to it

Solution

The black ball in motion possessed kinetic energy. The white ball, which was initially stationary, had zero kinetic energy. It gained kinetic energy from the moving black ball and started to roll.

The correct answer is B.

Why alternative A is wrong:

Heat energy is not transferred because the temperature of the balls remains the same before and after the collision. Hence, this alternative is incorrect.

Why alternative C is wrong:

Since the position of the black and white balls with respect to the ground remains the same, potential energy is not involved in the collision of the balls. Therefore, this alternative is incorrect.

Why alternative D is wrong:

The gravitational pull is not responsible for the balls rolling on a horizontal surface. It is responsible for the falling of objects. Hence, this alternative is incorrect.