It takes 500 watts to operate a machine whose power output is 480 watts. Which of the following is the efficiency of the machine

Q-1: It takes 500 watts to operate a machine whose power output is 480 watts. Which of the following is the efficiency of the machine? Is it

1) 20%
2) 48%
3) 96%
4) 98%
ANSWER: 3 -- 96%

Q-2: Which of the following statements is TRUE about an ELASTIC collision between two particles? Is it true that:

1) neither particle loses any of its kinetic energy
2) neither particle loses any of its momentum
3) the velocity gained by one particle is equal to that lost by the other
4) the total kinetic energy before and after the collision remains constant
ANSWER: 4 -- THE TOTAL KINETIC ENERGY BEFORE AND AFTER THE
COLLISION RE

Q-3:  Ten calories of heat are added to 2 grams of water. The temperature of the water rises to a total of how many degrees? Is it:

1) 2 degrees Celsius
2) 5 degrees Celsius
3) 10 degrees Celsius
4) 20 degrees Celsius
ANSWER: 3 -- 5 DEGREES CELSIUS

Q-4:  If water is warmed from 0 degrees Celsius to 6 degrees Celsius,which of the following things happen. Will the water:

1) expand steadily
2) contract steadily
3) expand at first and then contract
4) contract first then expand
ANSWER: 4 -- CONTRACT FIRST THEN EXPAND

Q-5: A gas at 0 degrees C and at normal atmospheric pressure has a volume of 273 cubic centimeters. If it is held at constant pressure until its volume is doubled, its temperature will be which one of the following? Will it be

1) 2 degrees Celsius
2) 200 degrees Celsius
3) 273 degrees Celsius
4) 546 degrees Celsius
ANSWER: 3 -- 273 DEGREES CELSIUS

Q-6:  Infrared rays are absorbed best by which one of the following. Is it:

1) bodies of air
2) white bodies with rough surfaces
3) mirrors
4) black bodies with rough surfaces
ANSWER: 4 -- BLACK BODIES WITH ROUGH SURFACES

Q-7: Energy stored in a body as thermal or internal energy consists of one of the following. Does it consist of:

1) heat in the form of radiant energy
2) molecular kinetic energy only
3) molecular potential energy only
4) both kinetic and potential energy
ANSWER: 4 -- BOTH KINETIC AND POTENTIAL ENERGY

Q-8:  When white light passes through a red plate of glass and then through a green plate of glass which one of the following things occur?

1) the light is totally absorbed
2) the light that emerges is a combination of red and green
3) the light that emerges lacks only its red and green components
4) the light that emerges is green
ANSWER: 1 -- THE LIGHT IS TOTALLY ABSORBED