11TNa IGCSE Electricity Quizizz

What advantage does a circuit-breaker have over a fuse in an electric circuit?

• A circuit-breaker provides an alternate route for the current to flow

• A circuit-breaker can be reset

• A fuse can be reset

• A fuse is more expensive

An appliance works at 3A. What is the best option for a fuse in the circuit connected to this appliance and why?

• 5A, so that the fuse does not blow when the appliance is used normally

• 7A, since it allows a current much larger than needed for the appliance to flow in the circuit

• 2A, so that the fuse blows when the appliance is used normally

• 3A, since the fuse blows at the same value of current that the appliance needs

When a metal wire is heated externally, its resistance will...?

• Stay constant

• Oscillate

• Increase

• Decrease

What is the equation linking charge, current and time?

• current = time x charge

• charge = current x time

• charge = current / time

• current = 1/2(time) x charge

Charging takes 110 minutes and causes a total charge of 180 000 C to pass through the battery. What is the average charging current in the battery?

• 1636 A

• 163.6 V

• 27 A

• 27 V

The current in a motor is 2.1 A and the potential difference across it is 12V. The motor takes 1.5 seconds to lift a mass. What is the energy transferred to the motor as it lifts the mass?

• 85 J

• 3.8 J

• 38 J

• 8.5 J

What is the difference between a.c. and d.c?

• d.c. is always a bigger current than a.c.

• a.c. is always a bigger current than d.c.

• a.c. remans constant in direction of current flow whereas d.c. oscillates in direction of current flow

• a.c. oscillates in direction of current flow whereas d.c. remains constant in direction of current flow

• There is no difference

The torch uses a light-emitting diode (LED) to provide light. When the LED is on, it shows that...

• the current is alternating

• the torch is switched off

• there is a current in the circuit

• there is a fault in the circuit

Calculate the voltage across the fixed resistor.

• 0.3 V

• 3 V

• 4.8 V

• 12 V

The components are a metal wire at constant temperature, a diode and a filament lamp, which letter represents the correct graph for a filament lamp?

• J

• K

• L

• none