IGCSE Physics MCQs 16-21 - Electricity & Magnetism

Which circuit symbol represents a component used to measure electric current?

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Four wires are made of the same metal. Which wire has the greatest resistance?

• a 100 cm long wire with a diameter of 3.0 mm
• a 100 cm long wire with a diameter of 6.0 mm
• a 10 cm long wire with a diameter of 3.0 mm
• a 10 cm long wire with a diameter of 6.0 mm

What happens to the reading on the voltmeter?

• It keeps increasing.

• It quickly increases and stays at maximum.

• It quickly increases and then decreases.

• It stays on zero.

A student uses four ammeters P, Q, R and S to measure the current in different parts of the circuit shown. Which two ammeters read the largest current?

• P and Q

• P and R

• R and Q

• R and S

Which action will demagnetise a magnetised piece of steel?

• Cool it in a freezer for several hours.
• Hit it repeatedly with a hammer.
• Put it in a coil carrying a direct current (d.c.).
• Put it near an unmagnetised piece of iron.

A student investigates electromagnetic induction. She moves the N pole of a magnet quickly towards a coil of wire. There is a reading on the galvanometer. What can she do to get a greater reading on the galvanometer?

• Hold the bar magnet stationary inside the coil.

• Move the bar magnet slowly away from the coil.

• Use a coil of wire with fewer turns on it.

• Use a stronger bar magnet.

Which diagram shows the magnetic field around a straight, current-carrying wire?

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Which graph shows the voltage output of an a.c. generator with the peaks and zeros correctly labelled

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Several cells are connected in series, as shown. What is the combined electromotive force (e.m.f.) of the cells?

• the average of the e.m.f.s of the separate cells
• the e.m.f. of one of the cells
• the product of the e.m.f.s of the cells
• the sum of the e.m.f.s of the cells

A student uses three small plotting compasses to investigate the magnetic field around a bar magnet. Which diagram shows the directions in which the compass needles point?

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