OCR Gateway GCSE Physics A topic P4 Magnetism and magnetic fields overview quiz quiz

It is attracted to a nearby magnet

It is made of a shiny metal such as steel

It can repel another magnet

It is heavy and feels dense in the hand

From south to north

In circles around the magnet

Straight up

From north to south

Iron, steel, cobalt and nickel

Copper, aluminium, gold and silver

All metals, since every metal is magnetic

Only iron and nothing else at all

No magnetic field at all, no matter how large the current

A field like a bar magnet, strong and uniform inside

A single straight field line running along the central axis

A field that points only outwards, away from the coil

Decreasing the current

Using fewer turns

Adding an iron core

Removing the core

A magnet inducing a current in a nearby stationary coil of wire

Two magnets attracting because their opposite poles face each other

A wire heating up and glowing when a large current flows through it

A current-carrying wire experiencing a force in a magnetic field

The force (motion)

The magnetic field

The current

The voltage

When a magnet is held perfectly still somewhere inside the coil

When the magnetic field through the coil is changing

When the coil is warmed up by a nearby flame

Only when the coil is connected to a steady battery

Direct current is far too dangerous to be passed safely through any transformer coil at all

Alternating current is much cheaper to generate, so engineers simply choose it for transformers

A steady direct current gives an unchanging field, so no voltage is induced in the secondary

Direct current is unable to flow through the copper coils of a transformer at all

To make the transmission cables glow brightly so that engineers can spot any faults easily

Because a very high transmission voltage is far safer to touch directly than a low voltage would be

To increase the resistance of the cables so that much less current is able to flow along them

To raise the voltage so the current is lower, reducing the energy wasted as heat in the cables