Physics 9702/31 — October/November 2019

• Place the $10\ \Omega$ resistor in component holder P.
• Place the $22\ \Omega$ resistor in component holder Q.
• Set up the circuit shown in Fig. 1.1.

• K and L are crocodile clips.

The resistor in component holder Q has resistance $R$.

Place L approximately half-way along the wire.

• The distance between K and L is $d$, as shown in Fig. 1.1.

Record $R$ and $d$.

$R$ = ______
$d$ = ______

• Close the switch.

• Record the voltmeter reading $V$.

$V$ = ______

• Open the switch.

• Change the resistor in Q. Do not change the resistor in P.

• Record the new value of $R$.

$R$ = ______

• Close the switch.

• Change the position of L on the wire so that the voltmeter reading is as close as possible to the value for $V$ in (a).

• Record $d$.

$d$ = ______

• Open the switch.

• Write down your value of $V$ from (a).

$V$ = ______

• Repeat (b) until you have six sets of readings of $R$ and $d$. Include your readings from (a) and (b).

Record your results in a table. Include values of $\frac{R}{d}$ in your table.

It is suggested that the quantities $R$ and $d$ are related by the equation

$$\frac{R}{d} = AR + B$$

where $A$ and $B$ are constants.

Using your answers in (d)(iii), determine values for $A$ and $B$. Give appropriate units.

$A$ = ______
$B$ = ______