Physics Questions - Module #23
• Feel free to use the questions below to check (or improve) your understanding of the concepts in this physics module.

1. What is the source of the electrons that heat up your clothes iron
1. a hydroelectric dam
2. a coal power plant
3. the power outlet in your home
4. a nuclear power plant
6. the moon shining on your clothes-iron
7. atoms in the filament of your clothes-iron

2. You buy a hair-dryer in another country and it is rated at 220 V. If you plug it into a 110 V outlet, the current in the dryer is ___ compared to if you plug it into a 220 V outlet.
1. the same
2. two times greater
3. four times greater
4. 110 times greater
5. half
6. a quarter

3. Three light-bulbs are connected in parallel across a battery. One has a thick filament, one a thin filament, and one a medium filament. Which one has the lowest voltage across the lamp.
1. Medium filament
2. thin filament
3. thick filament
4. there is no voltage across the filaments
5. voltage is the same across all three filaments

4. A light bulb is connected to a 200 V power source. A current of 2.0 Amps flows across the bulb. How much power is being dissipated by the bulb?
1. 200 W
2. 400 W
3. 100 W
4. 50 W
5. 800 W
6. none of the above

5. A voltage of 30 V is applied across a 30 ohm resistor. What is the current flowing through the resistor.
1. 0 Amps
2. 1 Amp
3. 2 Amps
4. 900 Amps
5. 300 Amps
6. 30 Amps