NTSE SAT Physics Electricity Heating Effect Of Current Electric Energy and Electric Power MCQs

Question: Correct power rating of bulb used in our country (India):

• a) 100 volt
• b) 100 volt
• c) 100 W - 220 volt
• d) 10 volt

Answer: 100 W - 220 volt

Question: Number of Joules in kWh is :

• a) 3.6 × 107 
• b) 3.6 × 106 
• c) 3.6 × 105 
• d) 3.6 × 104

Answer: 3.6 × 106 

Question: An electric iron of heating element of resistance 88 Ω is used at 220 volt for 2 hours. The electric energy spent, in unit, will be :

• a) 0.8
• b) 1.1
• c) 2.2
• d) 8.8

Answer: 1.1

Question: Two identical heater wires are first connected in series and then in parallel with a source of electricity. The ratio of heat produced in the two cases is :

• a) 2 : 1
• b) 1 : 2
• c) 4 : 1
• d) 1 : 4

Answer: 1 : 4

Question: You are given three bulbs 25 W, 40 W and 60 W. Which of them has the lowest resistance ?

• a) 25 watt bulb
• b) 40 watt bulb
• c) 60 watt bulb
• d) Insufficient data

Answer: 60 watt bulb

Question: An electric heater can boil a certain amount of water in 10 minute and another heater can do it in 15 minute, both working at the same voltage. If the two heaters are connected in parallel across the same voltage as before how much time will they take to boil the same amount of water ?

• a) 9 min
• b) 12.5 min
• c) 7.5 min
• d) 6 min

Answer: 6 min

Question: Two identical heater wires are first connected in series and then in parallel with a source of electricity. The ratio of heat produced in the two cases is :

• a) 2 : 1
• b) 1 : 2
• c) 4 : 1
• d) 1 : 4

Answer: 1 : 4

Question: An electric heater can boil a certain amount of water in 10 minute and another heater can do it in 15 minute, both working at the same voltage. If the two heaters are connected in parallel across the same voltage as before how much time will they take to boil the same amount of water ?

• a) 9 min
• b) 12.5 min
• c) 7.5 min
• d) 6 min

Answer: 6 min

Question: You are given three bulbs 25 W, 40 W and 60 W. Which of them has the lowest resistance ?

• a) 25 watt bulb
• b) 40 watt bulb
• c) 60 watt bulb
• d) Insufficient data

Answer: 60 watt bulb

Question: Correct power rating of bulb used in our country (India):

• a) 100 volt
• b) 100 volt
• c) 100 W - 220 volt
• d) 10 volt

Answer: 100 W - 220 volt