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P2: Quiz 12 – Answers

P2: Quiz 12 – Answers

1) energy, work, resistance, fall

A power supply (cell or battery) does work on a charge and transfers

2) energy transfer = charge flow x potential difference, or E = QV

Energy transferred is measured in joules (J), charge flow is measured in coulombs (C) and potential difference is measured in volts (V).

A power supply (cell or battery) does work on a charge and transfers

**ENERGY**to it to increase its potential difference. When a charge passes through a component, it does**WORK**against the**RESISTANCE**of the component, which transfers energy to the component and results in a**FALL**in potential difference.2) energy transfer = charge flow x potential difference, or E = QV

Energy transferred is measured in joules (J), charge flow is measured in coulombs (C) and potential difference is measured in volts (V).

3) 3,600 J

4) 8 V

5) 900 C

6) charge flow = current x time, or Q = IT

Charge flow is measured in coulombs (C), current is measured in amps (A) and time is measured in seconds (S)

3) 3,600 J

4) 8 V

5) 900 C

6) charge flow = current x time, or Q = IT

Charge flow is measured in coulombs (C), current is measured in amps (A) and time is measured in seconds (S)

7)

a) 480 C

b) 2,880 J

8) 51,840 J (or 51.84 KJ)

**Questions**

1) Fill in the gaps in the paragraph below.

A power supply (cell or battery) does work on a charge and transfers ______ to it to increase its potential difference. When a charge passes through a component, it does ______ against the ______ of the component, which transfers energy to the component and results in a ______ in potential difference.

2) Write down the equation that links charge flow, energy transferred and potential difference. Give the units for each of the variables. Also, write down the formula triangle.

3) A motor in a battery powered fan has a potential difference of 9 V. Calculate the energy transferred if 400 coulombs of charge pass through the motor of the battery powered fan.

4) A circuit transfers 2,800 joules of energy when 350 coulombs of charge travels around the circuit. Calculate the potential difference in the circuit.

5) 10.8 kJ of energy is transferred in a circuit that has a potential difference of 12 V. Calculate the charge flow in the circuit.

6) Write down the equation that links current, charge flow and time. Give the units for each of the variables. Also, write down the formula triangle.

7) We have the circuit below with a single filament bulb.

The cell has a potential difference of 6 V and the current in the circuit is 2 A. The filament bulb is on for 4 minutes.

a) Calculate the charge flow during the 4 minutes that the filament bulb is on for.

b) Calculate the energy transferred during the 4 minutes that the filament bulb is on for.

8) An electric motor in a circuit has a potential difference across it of 12 V and a current through it of 4.8 A. Calculate the energy transferred to the electric motor when it is on for 15 minutes.

a) Calculate the charge flow during the 4 minutes that the filament bulb is on for.

b) Calculate the energy transferred during the 4 minutes that the filament bulb is on for.

8) An electric motor in a circuit has a potential difference across it of 12 V and a current through it of 4.8 A. Calculate the energy transferred to the electric motor when it is on for 15 minutes.