# Worksheet: Capacitors

In this worksheet, we will practice converting between common units of capacitance and describing how capacitors work in circuits.

Q1:

As a capacitor is charged, the amount of charge on it , and the potential difference across it .

• Bincreases, remains constant
• Cdecreases, increases
• Dincreases, increases
• Eincreases, decreases

Q2:

What is 3.2 mF in microfarads?

Q3:

What is 0.56 F in millifarads?

Q4:

• A0.001
• B
• C
• D10
• E

Q5:

The diagram shows a circuit containing a capacitor, a resistor, and a switch connected in series. The capacitor is initially charged, and the switch is initially open. What is the magnitude of the current through the circuit immediately after the switch is closed?

Q6:

As a capacitor discharges, the amount of charge on it , and the potential difference across it .

• Aincreases, decreases
• Bdecreases, remains constant
• Cincreases, increases
• Ddecreases, decreases
• Edecreases, increases

Q7:

The diagram shows a circuit containing a capacitor and a resistor. The capacitor is discharging, and there is an electric current through the circuit.

What would happen if a capacitor were allowed to discharge through the same circuit, but without the resistor?

• AThe capacitor would discharge more slowly.
• BThe capacitor would not discharge.
• CThe capacitor would explode.
• DThe capacitor would discharge almost instantaneously.
• EThe current through the wire would cause it to melt.

Q8:

If the charge on a capacitor is , then the potential difference across it .

• Bincreased, stays the same
• Cdecreased, stays the same
• Dincreased, increases
• Eincreased, decreases

Q9:

Diagram (A) shows a circuit consisting of a cell, a switch, a capacitor, and a resistor connected in series. Which of the four graphs in diagram (B) correctly shows the potential difference across the capacitor against time when the switch is closed?

• A(a)
• B(c)
• C(b)
• D(d)

Q10:

What is 89 µF in millifarads?

Q11:

The diagram shows a circuit containing a capacitor, a resistor, and a switch connected in series. The capacitor is initially fully charged, and the switch is initially open. Immediately after the switch is closed, the current through the circuit is 0.2 A. What was the potential difference across the capacitor when it was fully charged?

Q12:

A capacitor is connected to a cell and allowed to fully charge. What is the potential difference across the capacitor once it has fully charged?

Q13:

What is 24 mF in farads?

Q14:

Which of the four circuit symbols shown in the diagram represents a capacitor?

• A(b)
• B(a)
• C(c)
• D(d)

Q15:

The diagram shows a circuit that charges a capacitor. Once charged, which side of the capacitor, or , will be positively charged?

• A
• B

Q16:

Which of the following is the correct unit for measuring capacitance?

• AAmpere (A)
• BHertz (Hz)
• CCoulomb (C)