(a)[1]
In the space below, draw a circuit diagram that includes a battery, a switch, a fixed resistor and a variable resistor, all joined in series.
(b)[1]
The c.r.o. is used to measure the voltage across the fixed resistor. On your circuit diagram, mark the two points $A$ and $B$ where the c.r.o. connects to the circuit.
(c)[1]
State which control knob is adjusted to move the dot to the centre of the screen, as shown in Fig. 3.1b.
(d(i))[1]
Calculate the voltage $V_{AB}$ across the fixed resistor.
(d(ii))[1]
The resistance of the variable resistor is reduced. State what happens to the dot on the screen.