```         (a)  ultrasonic waves
(b)  infrasonic waves
(d)  audible sound waves
Ans : (a)
313. When you pull out the plug connected to an electrical appliance, you often observe a spark. To which property of the appliance is
this related? [CDS 2011]
(a) Resistance
(b) Inductance
(c) Capacitance
(d) Wattage
Ans : (c)
314. If the door of a running refrigerator in a closer room is kept open, what will be the net effect on the room? [CDS 2011]
(a) It will cool the room
(b) It will heat the room
(c) It will make no difference on the average
(d) lt will make the temperature go up and down
Ans : (b)
315. When a ball drops onto the floor it bounces. Why does it bounce? [CDS 2011]
(a) Newton"s third law implies that for every action (drop) there is a reaction (bounce)
(b) The floor exerts a force on the ball during the impact
(c) The floor is perfectly rigid
(d) The floor heats up on impact
Ans : (a)
316. A body has a mass of 6 kg on the Earth; when measured on the Moon, its mas would be [CDS 2011]
(a) Nearly 1 kg
(b) less than 1 kg
(c) less than 6 kg
(d) 6 kg
Ans : (d)
317. Transformer is a kind of appliance that can
1) increase power
2) increase voltage
3) decrease voltage
4) measure current and voltage
Select the .correct answer using the code given below: [CDS 2011]
(a)   1 and 4
(b)   4 only
(c)   2 and 3 only
(d)   2, 3 and 4
Ans : (c)
318. At the time of short-circuit the current in the circuit [Asstt Commdt 2011]
(a) reduces substantially
(b) does not change
252
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