Electrical power and safety Quiz
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5 questions, one answer each
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1. A 12 V motor draws a current of 3.0 A. What is its power?
- A. 4.0 W
- B. 15 W
- C. 36 W
- D. 0.25 W
2. A 2.0 kW heater is on for 30 minutes. How much energy does it transfer?
- A. 60 kWh
- B. 1.0 kWh
- C. 4.0 kWh
- D. 0.25 kWh
3. Electricity costs 20 cents per kWh. What does 3.0 kWh cost?
- A. 60 cents
- B. 6.7 cents
- C. 23 cents
- D. 0.60 cents
4. What is the main job of the earth wire?
- A. To carry the normal current to the appliance
- B. To complete the circuit
- C. To make the appliance work faster
- D. To let a large fault current flow away and blow the fuse
5. A balloon rubbed on hair becomes negatively charged. What has happened?
- A. Protons moved from the balloon to the hair
- B. Protons moved from the hair to the balloon
- C. Electrons moved from the hair to the balloon
- D. Electrons moved from the balloon to the hair