In the circuit there are two fixed resistors and a light-dependent resistor (LDR). Fig. 8.1 indicates that the power supply is a 9.0 V battery.
Fig. 8.1 presents a 9.0 V battery, a 450 Ω resistor, an 800 Ω resistor and an LDR connected in a circuit.
(a)[1]
State the meaning of electric current.
(b)[1]
Complete the equation linking the current in the 450 Ω resistor with $I_1$ and $I_2$.
(c)[4]
Calculate the power dissipated by the 800 Ω resistor.
(d)[3]
Explain how the potential difference (p.d.) across the 450 Ω resistor changes.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Q / t or the charge flow rate / electrons” …