7 (a) Figure 15 shows three stages of a magnet moving into and then out of a coil of wire. The coil is connected to a milliammeter. (i) Which row of the table shows the deflection on the milliammeter for the three stages in Figure 15? magnet moving into coil magnet stationary inside coil magnet moving out of coil Figure 16 (ii) Give two ways of increasing the deflections on the milliammeter shown in Figure 16. 1 2 (b) Figure 17 is a diagram representing a loudspeaker. Explain how sound is produced when an alternating current is supplied to the coil of the loudspeaker. (c) Figure 18 shows a transformer. (i) State the purpose of the transformer shown in Figure 18. (ii) Calculate the output voltage of the secondary coil. Use an equation selected from the list of equations at the end of this paper.

GCSE Edexcel Physics Power: 7 (a) Figure 15 shows three stag

7 (a) Figure 15 shows three stages of a magnet moving into and then out of a coil of wire - Edexcel - GCSE Physics - Question 7 - 2020 - Paper 1

Question 7

7 (a) Figure 15 shows three stages of a magnet moving into and then out of a coil of wire. The coil is connected to a milliammeter. (i) Which row of the table shows... show full transcript

Worked Solution & Example Answer:7 (a) Figure 15 shows three stages of a magnet moving into and then out of a coil of wire - Edexcel - GCSE Physics - Question 7 - 2020 - Paper 1

Step 1

Which row of the table shows the deflection on the milliammeter for the three stages in Figure 15?

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Answer

In Figure 15, when the magnet moves into the coil, it induces a current, causing a deflection in the milliammeter. When the magnet is stationary within the coil, there is no change in the magnetic field, and thus no deflection is observed. As the magnet moves out of the coil, the current reverses, leading to a deflection in the opposite direction. Therefore, the correct row in the table would reflect a deflection while the magnet moves in, no deflection when stationary, and a deflection in the opposite direction as it moves out.

Step 2

Give two ways of increasing the deflections on the milliammeter shown in Figure 16.

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Answer

Increase the strength of the magnet used.
Increase the speed at which the magnet moves in and out of the coil.

Step 3

Explain how sound is produced when an alternating current is supplied to the coil of the loudspeaker.

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Answer

When an alternating current passes through the coil in the loudspeaker, it creates a varying magnetic field that interacts with the permanent magnet. This interaction causes the coil to move back and forth due to the forces of attraction and repulsion between the magnetic fields. The movement of the coil is transmitted to the paper cone attached to it, causing the cone to vibrate. These vibrations generate sound waves in the air, producing sound.

Step 4

State the purpose of the transformer shown in Figure 18.

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Answer

The purpose of the transformer is to step up or step down the voltage from the primary coil to the secondary coil.

Step 5

Calculate the output voltage of the secondary coil.

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Answer

Using the transformer equation, we have:

$\frac{V_p}{V_s} = \frac{N_p}{N_s}$

Substituting the values:

$\frac{230}{V_s} = \frac{18}{26}$

Rearranging gives:

$V_s = \frac{230 \times 26}{18}$

Calculating this yields:

$V_s = 330 \text{ V}$

7 (a) Figure 15 shows three stages of a magnet moving into and then out of a coil of wire - Edexcel - GCSE Physics - Question 7 - 2020 - Paper 1

Worked Solution & Example Answer:7 (a) Figure 15 shows three stages of a magnet moving into and then out of a coil of wire - Edexcel - GCSE Physics - Question 7 - 2020 - Paper 1

Which row of the table shows the deflection on the milliammeter for the three stages in Figure 15?

Give two ways of increasing the deflections on the milliammeter shown in Figure 16.

Explain how sound is produced when an alternating current is supplied to the coil of the loudspeaker.

State the purpose of the transformer shown in Figure 18.

Calculate the output voltage of the secondary coil.

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