Heating Effect of Electric Current, Class 10 Science NCERT Solutions

1. There will be total 20 MCQ in this test.
2. Please keep a pen and paper ready for rough work but keep your books away.
3. The test will consist of only objective type multiple choice questions requiring students to mouse-click their correct choice of the options against the related question number.
4. No negative marking for incorrect choice.
5. Please click on “Finish the Test” when you want to exit.
6. All the best – Happy Studying

1. If the current passing through a heater is halved, then the heat produced by it becomes

H/2

H/4

Question 1 of 20

2. 1 kilowatt-hour is equal to

a) 3600 J

b) 3.6 × 10⁶ J

c) 4.6 × 10⁶ J

d) 3.6 × 10⁵ J

Question 2 of 20

3. An electric bulb is marked 18watt-240 volt. If it is used across 240 V power line for one hour daily, calculate the number of days to consume 1 unit of electric energy.

54.5 days

57.5 days

50.5 days

55.5 days

Question 3 of 20

4. Two bulbs marked 200 watt-250 volts and 100 watt-250 volts are joined in series to 250 volts supply. Power consumed in circuit is

67 watt

100 watt

300 watt

33 watt

Question 4 of 20

5. In the following circuits (Figure 12.2), heat produced in the resistor or combination of resistors connected to a 12 V battery will be:

minimum in case (i)

maximum in case (iii)

maximum in case (ii)

same in all cases

Question 5 of 20

6. Which of the following terms does not represent electrical power in a circuit?

i) V²/R

ii) I²R

iii) IR²iv) VI

ii)

iii)

iv)

Question 6 of 20

7. The resistance of a conductor increases with-
I: Increase in length
II: Increase in volume
III: Decrease in area

I or III

II only

I or II

III only

Question 7 of 20

8. How much heat energy is produced in 10 second in an electric iron having resistance 440 Ω, when a potential difference of 220 volt is applied across it?

1200 J

600 J

1000 J

1100 J

Question 8 of 20

9. An electric refrigerator rated 500 W operates 10 hr per day. What is the cost of the energy to operate it for 30 days at Rs. 4.00 per kWh?

Rs. 600

Rs. 400

Rs. 500

Rs. 800

Question 9 of 20

10. Two light bulbs P and Q are identical in all respects, except that P’s filament is thicker than Q’s. If the same potential difference is applied to each, then

P will burn brighter because it has the lower resistance

Q will burn brighter because it has the lower resistance.

Q will burn brighter because it has the greater resistance.

P will burn brighter because it has the greater resistance.

Question 10 of 20

11. Find the potential difference across the resistor, when 125 J of heat is produced each second in a 5 ohm resistor.

25 V

30 V

20 V

28 V

Question 11 of 20

12. A bulb is rated as 270V, 0.5 A. Its power is

125 watt

100 watt

60 watt

135 watt

Question 12 of 20

13. How much energy is transferred when 10 A current flows through a resistor of 5 ohm for 30 minutes?

0.25 kWh

1.2 kWh

0.025 kWh

3.2 kWh

Question 13 of 20

14. Two light bulbs are marked 230 V; 75 W and 230 V; 150 W. If the first bulb has a resistance R, then the resistance of the second is;

(1/2)R

(1/4) R

Question 14 of 20

15. A certain wire has a resistance R. The resistance of another wire identical with the first and having twice its diameter is;

0.5 R

0.25 R

4 R

2 R

Question 15 of 20

16. In the circuit shown, the bulb marked 2R has twice the resistance of the bulb marked R. Compared with bulb 2R, the current in bulb R is ____ and its brightness compared to the other bulb, is ______.

smaller, brighter

smaller, dimmer

larger, brighter

larger, dimmer

Question 16 of 20

17. Commercial unit of electric energy is

volt

joule

watt

Kilowatt-hour

Question 17 of 20

18. Which effect is utilized by an electric bulb?

Power effect

Chemical effect

Magnetic effect

Heating effect

Question 18 of 20

19. How much heat is generated when current I is passed through a resistor for time t?

a) VI/t

b) IR²t

c) I²R/t

d) I²Rt

Question 19 of 20

20. Two lamps, one rated 40W – 240 V and the other 60W- 240V are connected in parallel to 240 V supply. What current is drawn from the supply line?

0.216 A

0.816 A

0.416 A

0.616 A

Question 20 of 20