Electrical Fundamental Assignment 3

1. How many watts does 6000 J in 100 ms equal?

2. If it takes 300 ms to use 10,000 J of energy, the power is

(a) 33.3 kW (b) 33.3 W (c) 33.3 mW

3. If you used 500 W of power for 24 h, you have used

(a) 0.5 kWh (b) 2,400 kWh (c) 12,000 kWh (d) 12 kWh

4. A 22 Ω half-watt resistor and a 220 Ω half-watt resistor are connected across a 10 V source. Which one(s) will overheat?

(a) 22 Ω (b) 220 Ω (c) both (d) neither

5. A 100 Ω resistor must carry a maximum current of 35 mA. Its rating should be at least

(a) 35 W (b) 0.05 W (c) 123 mW (d) 0.5 W

6. A given power supply can provide 8 A for 2.5 h. Its ampere-hour rating is

(a) 2.5 Ah (b) 20 Ah (c) 8 Ah

7. A 12 V battery is connected to a 600 Ω load. Under these conditions, it is rated at 50 Ah. How long can it supply current to the load?

(a) 2,500 h (b) 50 h (c) 25 h (d) 4.16 h

8. The picture shows a 3.7V, 2200mAh Li-ion battery that is used for wireless gaming headset. How long will the battery last on one full charge if the headset is pulling 50 mA current.

9. If a 75 V source is supplying 2 A to a load, what is the resistance value of the load?

10. What is the power when there are 500 mA of current through a 4.7 kΩ resistor?