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• red green violet

• red violet green

• violet green red

• violet red green

• radio visible light X-rays

• radio X-rays ultrasound

• X-rays radio ultrasound

• X-rays visible light radio

• increasing the number of turns in the coil

• placing the magnets further apart

• using a coil made from steel wire

• reversing one of the magnets

• increasing the current

• reversing the current

• increasing the strength of the magnetic field

• using an electromagnet with the same polarity as the permanent magnet

What is a transformer used for?

• changing a direct current into an alternating current

• changing the magnitude of an alternating voltage

• reducing the frequency of an alternating current

• switching off the current in a circuit when there is a fault

What are the relative charges on a proton, a neutron and an electron?

• 0 –1 +1

• 0 –1 –1

• +1 0 –1

• +1 0 +1

• The light changes colour as it passes through the prism.

• The light forms a brighter spectrum.

• There is no reflected light.

• There is no dispersion of the emerging light.

• A

• B

• C

• D

• increasing the current

• reversing the current

• increasing the strength of the magnetic field

• using an electromagnet with the same polarity as the permanent magnet

What is a transformer used for?

• changing a direct current into an alternating current

• changing the magnitude of an alternating voltage

• reducing the frequency of an alternating current

• switching off the current in a circuit when there is a fault