# Worksheet: The Power of Electrical Components

In this worksheet, we will practice using the formula E = QV to find the energy dissipated to the environment by the component of an electronic circuit.

**Q2: **

Which of the following is the correct formula for the energy transferred to the environment when an amount of a charge, , is moved across a potential difference, ?

- A
- B
- C
- D
- E

**Q4: **

Which of the following is the correct formula for the power supplied to a component of an electrical circuit? is the power supplied to the component, is the current through the component, is the potential difference across the component, and is the resistance of the component.

- A
- B
- C
- D
- E

**Q6: **

A 45 mW LED is connected to a 9 V battery and left on for 30 seconds. How much charge passes through the LED over this time?

**Q7: **

The potential difference across a resistor in a circuit is 10 V. If 150 C of charge passes through the resistor, how much energy is dissipated to the environment by the resistor?

**Q8: **

A piece of connecting wire in a circuit is 20 cm long. It has a resistance of 0.02 Ω and dissipates energy to its environment as heat at a rate of 2 W. How much is the current passing through the wire?

**Q9: **

A 4 A current passes through a 10 Ω resistor. How much is the power of the resistor?

**Q11: **

A resistor in a circuit has a potential difference of 12 V across it. It dissipates energy to its environment in the form of heat at a rate of 48 W. How much charge passes through the resistor in 2 minutes?

**Q12: **

The diagram shows a circuit consisting of three identical resistors connected to a cell. At what rate does one resistor dissipate energy to the surrounding environment?