What is the power of a 3V light bulb with 20 A running through it?

• 0.15 W

• 0.45 W

• 60 W

• 6.67 W

A light circuit is operating at 75 Volts. What is the current if the resistance is 5 Ohms?

• 375 Amps

• 50 Amps

• 15 Amps

• 0.07 Amps

What is the best definition for potential difference?

• the potential energy per electron.

• the potential energy per unit of charge.

• the kinetic energy per unit of charge.

• the energy carried by an electron.

A student used some everyday items to investigate static electricity.

Figure 1 shows a flexible plastic strip being rubbed with a cloth. Rubbing the plastic strip with the cloth causes the strip to become negatively charged because ____________________ move from the cloth onto the plastic strip.

• electrons

• protons

• neutrons

• ions

The graph below shows how the current through a filament lamp changes after the lamp is switched on.

The normal current through the filament lamp is 1.5 A.

For how many seconds is the current through the filament lamp greater than 1.5 A?

• 0.01 s

• 0.08 s

• 0.09 s

• 0.14 s

LED lamps are much more efficient than filament lamps.

What does this statement mean?

• LED lamps have a similar power output to filament lamps.

• LED lamps waste a smaller proportion of the input energy than filament lamps.

• LED lamps have a higher power input than filament lamps.

• LED lamps waste a larger proportion of the input energy than filament lamps.

The diagram shows a temperature sensing circuit used to control a heating system in a house.

What quantity does the ammeter measure?

• Current

• Potential difference

• Resistance

• Power

The diagram shows a temperature sensing circuit used to control a heating system in a house.

The current in the circuit is 3.5 mA when the potential difference across the thermistor is 4.2 V

Calculate the resistance of the thermistor in Ohms.

• 1200

• 1.2

• 14.7

• 0.0147

Figure 1 shows the inside of a battery pack designed to hold three identical 1.5 V cells.

Which one of the arrangements shown in Figure 2 would give a 4.5 V output across the battery pack terminals T?

• 
• 
• 
• 

The battery in the drone can store 97.5 kJ of energy.

When the drone is hovering, the power output of the battery is 65.0 W

Calculate the time in seconds for which the drone can hover.

• 1 500

• 5 850

• 1.5

• 6 337 500