Have an account?
Skip to Content
Build your own quiz
Suggestions for you
14 questions
Show Answers
See Preview
- 1. Multiple Choice
Which graph shows the output voltage from a simple a.c. generator?
- 2. Multiple Choice
A transformer has 50 turns on its primary coil and 100 turns on its secondary coil. An a.c. voltage
of 25.0 V is connected across the primary coil.
What is the voltage across the secondary coil?
A 12.5V
B 50V
C 175V
D 200V
- 3. Multiple Choice
The diagram shows an electrical device.
What is this electrical device?
A a d.c. motor
B an a.c. generator
C a magnetising coil
D a transformer
- 4. Multiple Choice
The graph shows the voltage input to a step-down transformer.
Which diagram shows the voltage output from the transformer?
- 5. Multiple Choice
The diagram shows an a.c. generator.As the coil passes through the position shown, the output voltage is +10 V. When does the output voltage become –10 V?
A when the coil has turned through 90°
B when the coil has turned through 180°
C when the coil has turned through 270°
D when the coil has turned through 360°
- 6. Multiple Choice
A wire is placed in a strong magnetic field. When a current is passed through the wire it moves upwards, as shown.
The current is reversed.
In which direction does the wire move?
A downwards
B towards the north pole
C towards the south pole
D upwards
- 7. Multiple Choice
The diagram shows a coil of wire between the poles of a magnet.
The coil consists of 20 turns of insulated wire.
The coil is connected to a variable resistor and a power supply. How can the turning effect on the coil be increased?
A by moving the poles of the magnet closer to the coil
B by reducing the number of turns on the coil while keeping the current constant
C by increasing the resistance of the variable resistor
D by reversing the terminals of the power supply
- 8. Multiple Choice
step-down transformer is used to light a 12 V lamp from a 240 V mains supply. The lamp lights at normal brightness. The primary coil has 600 turns.
How many turns are in the secondary coil?
A 12
B 20
C 30
D 50
- 9. Multiple Choice
When a wire is moved upwards between the poles of a magnet, an electromotive force (e.m.f.) is
induced across the ends of the wire.
Which device uses a moving wire to induce an e.m.f.?
A a cathode-ray tube
B a generator
C a transformer
D an electromagnet
- 10. Multiple Choice
he diagram shows cables used in the transmission of electrical energy. High voltages are used for the transmission.
A Fear of high voltages stops people from interfering with the cables.
B Heat loss in the cables is smaller than if low voltages are used.
C High voltages increase the current in the cables.
D High voltages produce large magnetic fields, so less insulation is needed.
- 11. Multiple Choice
Which activity will produce the highest current?
Move the magnet bar into the coil while the coil remains stationery
Move the coil into the magnet bar while the magnet remains stationery
Move the coil and magnet towards each other
Move the coil and magnet away from each other
- 12. Multiple ChoiceHow could the experimenter increase the amount of electricity being induced by this experiment?Increase the number of coilsDecrease the number of coilsFlip the magnet aroundNothing, the amount of electricity cannot be increased
- 13. Multiple Choice
How can a permanent magnet be demagnetised?
A Cool the magnet for a long time.
B Place it next to another magnet.
C Slowly pull it out of a coil connected to an a.c. supply.
D Slowly pull it out of a coil connected to a d.c. supply.
- 14. Multiple Choice
A circuit contains a fixed resistor connected in series with a thermistor and an ammeter.
Which row shows how temperature change affects the resistance of the thermistor and the current in the circuit?
A
B
C
D
- Answer choicesTagsAnswer choicesTags