Electrical power and energy Quiz
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5 questions, one answer each
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1. A lamp carries 3.0 A at 12 V. What is its power?
- A. 4.0 W
- B. 15 W
- C. 36 W
- D. 0.25 W
2. A 500 W appliance runs for 60 s. How much energy does it transfer?
- A. 30 000 J
- B. 8.3 J
- C. 560 J
- D. 500 J
3. A 3.0 kW heater runs for 2.0 hours. How many kWh does it use?
- A. 1.5 kWh
- B. 5.0 kWh
- C. 3.0 kWh
- D. 6.0 kWh
4. An appliance receives 80 J of energy and transfers 60 J usefully. What is its efficiency?
- A. 133%
- B. 75%
- C. 20%
- D. 25%
5. A current of 2.0 A passes through a 5.0 Ω resistor. What is the power?
- A. 10 W
- B. 100 W
- C. 20 W
- D. 50 W