Fig. 8.1 illustrates 3 lamps together with a fuse linked to a power supply. The e.m.f. of the supply is $220\,\text{V}$. Each lamp is marked $220\,\text{V}, 40\,\text{W}$. The fuse is rated at $2.0\,\text{A}$.
(a(i))[2]
Calculate the current for each lamp.
(a(ii))[1]
Calculate the current through the fuse.
(a(iii))[2]
Calculate how many lamps, all in parallel, could be connected without blowing the fuse.
(b(i))[1]
Underline the effect this change has on the filament’s resistance: resistance increases / resistance remains the same / resistance decreases.
(b(ii))[2]
State and explain how this change affects the lamp’s power output.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applies I = P / V” …