Static electricity

Figure 1 shows a static electricity generator.

The rubber belt is turned by a motor.

As the rubber belt moves, charge is transferred from the rubber belt to the metal dome.

Figure 2 shows a student touching the metal dome of the static electricity generator.

The dome is negatively charged.

Complete the sentence.

Choose the answer from the box.

When the student touches the negatively charged metal dome the student’s hair

Complete the sentence.

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The hair on the student’s head stands up because the strands of hair experience

Which of the following diagrams shows the electric field pattern around the negatively charged metal dome?

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Figure 3 shows the negatively charged metal dome and an earthed conductor.

The air between the dome and the earthed conductor is an insulator.

Complete the sentence.

Choose the answer from the box.

The air between the dome and the earthed conductor has

The earthed conductor is moved closer to the metal dome.

A spark jumps from the dome to the earthed conductor.

Complete the sentence.

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The spark jumps because the air around the charged dome has

Which particles are transferred when the spark jumps from the negatively charged metal dome to the earthed conductor?

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The potential difference between the metal dome and earth is 300 000 V.

When the spark jumps there is a charge flow of 0.000 002 C.

Calculate the energy transferred by the spark.

Use the equation:

energy transferred = charge flow × potential difference

Figure 4 shows a static electricity generator.

The rubber belt is turned by a motor.

As the rubber belt moves, charge is transferred from the rubber belt to the metal dome.

Figure 5 shows a student touching the metal dome of the static electricity generator.

The dome is negatively charged.

Explain why the student’s hair stands up on end.

The charged metal dome creates an electric field.

What is an electric field?

How does the electric field strength vary as the distance from the charged metal dome increases?

Figure 6 shows the negatively charged metal dome and an earthed conductor.

When the earthed conductor is moved towards the metal dome, there is a spark between the dome and the earthed conductor.

The spark transfers 0.60 J of energy, and 2.0 μC of charge is transferred from the dome to the earthed conductor.

Calculate the potential difference between the metal dome and the earthed conductor.

Use the Physics Equations Sheet.

Which of the following changes would increase the distance a spark can jump between the dome and the earthed conductor?

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Scientists developed new models of the atom as new particles were discovered.

Draw one line from each particle to the year it was discovered.

The nucleus was discovered using an alpha particle scattering experiment. Alpha particles were directed at a sheet of gold foil. Figure 8 shows the paths taken by seven alpha particles, A, B, C, D, E, F and G.

Explain why alpha particle A takes the path shown in Figure 8.

Explain why the path of alpha particle B is more tightly curved than the path of alpha particle C.

What can be deduced about the atom from the paths taken by alpha particles D, E, F and G in Figure 8 ? Tick (✓) one box.

How is the Bohr model of the atom different from the nuclear model of the atom?

Explain how an electron can move up and down between energy levels in an atom.

Figure 3 shows a plastic rod being rubbed with a cloth.

The plastic rod becomes negatively charged.

Complete the sentences.

Choose answers from the box.

Each answer may be used once, more than once or not at all.

What charge is left on the cloth?

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The negatively charged plastic rod is put near another negatively charged plastic rod that is hanging from a string.

Figure 4 shows the two rods.

What force is exerted on the two rods?

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Give a reason for your answer.

There is an electric field around any charged object.

Which diagram shows the electric field pattern around a negatively charged sphere?

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In which position do two charged spheres experience the greatest electrostatic force?

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The rod became negatively charged and the cloth became positively charged.

Figure 6 shows the negatively charged rod on a balance.

Figure 7 shows another charged rod being held stationary above the rod on the balance. The rods do not touch each other.

Explain why the reading on the balance increases.

The balance had a zero error. The zero error is not important in this experiment. Give the reason why.

A negatively charged rod is held near an earthed conductor. Explain why a spark jumps between the negatively charged rod and the earthed conductor.

The ancient Greeks thought that atoms were tiny spheres that could not be divided into anything smaller. Since then, different discoveries have led to the model of the atom changing. Some of the discoveries are given in Table 1.

Which discovery was the earliest?

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Which discovery was the most recent?

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The alpha particle scattering experiment led to the nuclear model of the atom. Figure 5 shows the paths of alpha particles travelling close to a gold nucleus.

Complete the sentences. Choose answers from the box. Each answer may be used once, more than once or not at all.

Alpha particles and gold nuclei are both positively charged. The gold nucleus the alpha particles.

As the alpha particle approaches the gold nucleus, the electric field strength experienced by the alpha particle.

As an alpha particle approaches the gold nucleus, the force experienced by the alpha

The results of the alpha particle scattering experiment were reproducible. What does reproducible mean?

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Figure 12 shows a student after rubbing a balloon on his hair.

The balloon and hair have become charged.

Describe the force that acts on the student’s hair in Figure 12.

An earthed conductor was brought near the charged student. A spark jumped between the conductor and the student.

The potential difference between the conductor and the student was 2.5 kV The energy transferred by the spark was 0.0050 J

Calculate the charge transferred by the spark.

A defibrillator can transfer a charge to regulate a person’s heartbeat.

Figure 13 shows a defibrillator.

When the defibrillator is in use, a potential difference of 4800 V is applied across the person’s chest.

A charge of 0.16 coulombs passes through the person’s chest in 4.0 ms

Calculate the resistance of the person’s chest.

Figure 15 shows a student walking on a carpet.

Figure 15

The student becomes negatively charged because of the friction between his socks and the carpet.

Explain why the friction causes the student to become charged.

The student’s head is represented by the sphere in Figure 16.

The student is negatively charged. The arrow shows part of the electric field around the student’s head.

Draw three more arrows on Figure 16 to complete the electric field pattern.

Figure 16

The negatively charged student touches a metal tap and receives an electric shock.

Explain why.

Some carpets have thin copper wires running through them. The student is less likely to receive an electric shock after walking on this type of carpet.

Suggest why.

Figure 1 shows a student walking on a carpet.

The student becomes negatively charged because of the friction between his socks and the carpet.

Explain why the friction causes the student to become charged.

The student’s head is represented by the sphere in Figure 2.

The student is negatively charged. The arrow shows part of the electric field around the student’s head.

Draw three more arrows on Figure 2 to complete the electric field pattern.

The negatively charged student touches a metal tap and receives an electric shock.

Explain why.

Some carpets have thin copper wires running through them. The student is less likely to receive an electric shock after walking on this type of carpet.

Suggest why.