Class 8 Electricity Puzzles
1. Electric Energy: A 100 W bulb is used for 5 hours. How much energy is consumed in kWh?
Hint: Energy = Power × Time
Answer: 0.5 kWh
2. Safe Current: A fuse allows a safe current of 10 A. What happens if 15 A flows through it?
Hint: A fuse breaks when the current exceeds the safe limit.
Answer: The fuse will blow to protect the circuit.
3. Power: An appliance uses 220 V and draws 2 A. Calculate the power it uses.
Hint: Power = Voltage × Current
Answer: 440 W
4. Safe Current: A wire can carry a maximum of 8 A. What will happen if 12 A flows through it?
Hint: Exceeding the safe current can cause overheating.
Answer: The wire may overheat and cause a fire hazard.
5. Electric Energy: A TV of 150 W is used for 3 hours daily. How much energy does it consume in one week?
Hint: Total Energy = Power × Time × Days
Answer: 3.15 kWh
6. Power: A light bulb operates on 240 V and uses 0.5 A. What is its power?
Hint: Power = Voltage × Current
Answer: 120 W
7. Safe Current: What is the safe current rating for a 5 A fuse in a circuit?
Hint: The safe current rating is the value marked on the fuse.
Answer: 5 A
8. Electric Energy: How much energy is consumed if a 500 W heater runs for 4 hours?
Hint: Energy = Power × Time
Answer: 2 kWh
9. Power: A fan uses 110 V and draws 1.5 A. What is its power?
Hint: Power = Voltage × Current
Answer: 165 W
10. Safe Current: Why is it important to use a fuse of the correct current rating?
Hint: A fuse protects the circuit from excessive current.
Answer: Using the correct rating prevents damage to the circuit or appliances.