N23 1B P

A teacher sets up the equipment for three demonstrations, P, Q and R.

In demonstration P, the magnet is moved to the right.

In demonstration Q, the switch is closed.

In demonstration R, the copper rod is moved vertically upwards.

Which demonstrations can be used to demonstrate electromagnetic induction?

• P and Q only

• P and R only

• Q and R only

• P, Q and R

A metal rod PQ rests on two horizontal metal wires that are attached to a battery. The rod lies

between the poles of a magnet.

When the switch is closed, the rod moves to the right.

What could be changed so that the rod moves to the left?

• Open the switch.

• Reverse the battery terminals and exchange the poles of the magnet.

• Reverse the battery terminals but without exchanging the poles of the magnet.

• Turn the metal rod around (P and Q exchanged).

A transformer in a computer is used to transform the mains voltage of 240 V to 12 V.

The number of turns on the secondary coil is 2000.

Which statement about the transformer is correct?

• It is a step-down transformer and has 100 turns on its primary coil.

• It is a step-down transformer and has 40 000 turns on its primary coil.

• It is a step-up transformer and has 100 turns on its primary coil.

• It is a step-up transformer and has 40 000 turns on its primary coil.

Atom P has 6 electrons, 6 protons and 6 neutrons.

Atom Q has 6 electrons, 6 protons and 7 neutrons.

Which statement is correct?

• Atom P has atomic number 12.

• Atom P has nucleon number 6.

• Atom Q has nucleon number 13.

• Atoms P and Q are different chemical elements.

α-particles, β-particles and -rays are emitted by radioactive nuclei when they decay.

Which emissions can be deflected by an electric field?

• α-particles, β-particles and γ-rays

• α-particles and β-particles only

• β-particles and γ-rays only

• γ-rays and α-particles only

The graph shows the count rate from a radioactive source over a period of time.

What is the half-life of the source?

• 0.5 h

• 1.0 h

• 1.5 h

• 3.0 h

A scientist carries out an experiment using a sealed source which emits β-particles. The range of

the β-particles in the air is about 30 cm.

Which precaution is the most effective to protect the scientist from the radiation?

• handling the source with long tongs

• keeping the temperature of the source low

• opening all windows in the laboratory

• washing his hands before leaving the laboratory

Which planet orbits the Sun between Mars and Saturn?

• Earth

• Jupiter

• Mercury

• Neptune

Which statement about the Sun is correct?

• The Sun is a dwarf star consisting mostly of hydrogen and oxygen.

• The Sun is a giant star consisting mostly of helium and carbon dioxide.

• The Sun is a medium-sized star consisting mostly of hydrogen and helium.

• The Sun is a medium-sized star consisting mostly of nitrogen and oxygen.

Which quantity does a light-year measure?

• angle

• distance

• speed

• time