F3QE

Which of the following materials is a good conductor of electricity?

• Rubber
• Wood
• Copper
• Glass

What happens to the total resistance when resistors are connected in parallel?

• Increases
• Decreases
• Remains the same
• Doubles

What is the SI unit of electrical energy?

• Joule
• Watt
• Coulomb
• Ohm

What remains constant in a series circuit?

• Voltage
• Resistance
• Power
• Current

In a parallel circuit, the total current is equal to:

• The current through the largest resistor
• The sum of currents in each branch
• The current in any single branch
• The current in the first branch only

Which of the following statements about a parallel circuit is true?

• The total resistance increases when more resistors are added.
• The voltage is different across each branch.
• The total resistance is less than the smallest resistor in the circuit.
• The total current decreases when a resistor is added.

Why is an appliance with a metal casing required to have an earth wire?

• To ensure the device operates efficiently
• To reduce the voltage of the live wire
• To direct any leakage current safely to the ground
• To prevent the device from overheating

A 20 Ohm resistor has a 5 A current passing through it. What is the voltage across the resistor?

• 25 V
• 50 V
• 75 V
• 100 V

A copper wire has a resistance of 5 Ohm. If the length of the wire is doubled while keeping the cross-sectional area the same, what is the new resistance?

• 2.5 Ohm
• 5 Ohm
• 10 Ohm
• 20 Ohm

Which of the following correctly defines electrical resistivity?

• Resistance per unit length of a material
• The ability of a material to conduct electric current
• Resistance per unit cross-sectional area of a material
• Resistance per unit length and cross-sectional area of a material