Figure 9 shows a lamp connected to a d.c - Edexcel - GCSE Physics Combined Science - Question 5 - 2022 - Paper 1

The power supplied to the lamp can be calculated using the formula:

$P = V \times I$

Substituting the given values:

$P = 4.5 \times 0.3 = 1.35 \text{ W}$

Therefore, the power supplied to the lamp is approximately 1.4 W.

In Figure 9, there is one lamp connected to the power supply, while Figure 10 has two identical lamps connected.

Since the total voltage remains the same, when two identical lamps are connected in parallel, the overall brightness of each lamp will be less than the single lamp in Figure 9. This is due to the fact that the current is divided between the two lamps, leading to a decrease in brightness for each individual lamp compared to the lamp in Figure 9.

The student should set up a simple circuit with the following components:

• A low voltage power supply
• A resistance wire (1 m)
• A measuring device (like an ohmmeter) to measure the resistance of 50 cm of the wire

The circuit diagram should connect these components in series for accurate measurements.

Direct current (d.c.) flows in one direction only and has a constant voltage. It is commonly used in batteries and electronic devices.

Alternating current (a.c.) changes direction periodically and varies in voltage over time. It is used in household electrical supplies because it can be easily transformed to different voltages for efficient transmission.