In this experiment, you will investigate combinations of resistors in an electrical circuit. Fig. 1.1 shows how resistors of resistance $68.0\ \Omega$ can be arranged to give different values of total resistance $R$. (a) ● Set up the circuit as shown in Fig. 1.2 with a resistor of resistance $68.0\ \Omega$ between F and G. ● Record the total resistance $R$ between F and G. $R$ = \_\_\_\_\_\_ $\Omega$ ● Close the switch. ● Record the ammeter reading $I$. $I$ = \_\_\_\_\_\_ ●…

Physics 9702/35 — October/November 2020

Cambridge AS Level · Advanced Practical Skills · worked solutions for every part, with the mark scheme

questions

marks

120

minutes

Topics Manipulation, Measurement and Observation · Presentation of Data and Observations · Analysis, Conclusions and Evaluation

Q1Manipulation, Measurement and ObservationPresentation of Data and ObservationsAnalysis, Conclusions and EvaluationFree sample

In this experiment, you will investigate combinations of resistors in an electrical circuit.

Fig. 1.1 shows how resistors of resistance $68.0\ \Omega$ can be arranged to give different values of total resistance $R$ .

Fig. 1.1

(a)

● Set up the circuit as shown in Fig. 1.2 with a resistor of resistance $68.0\ \Omega$ between F and G.

Fig. 1.2

● Record the total resistance $R$ between F and G.

$R$ = ______ $\Omega$

● Close the switch.

● Record the ammeter reading $I$ .

$I$ = ______

● Open the switch.

(b)

Use six different arrangements of the $68.0\ \Omega$ resistors to provide six different total resistances between F and G.

For each arrangement, record $R$ and $I$ in a table. Include values of $\frac{1}{I}$ in your table.

10M

(c)

(i)

Plot a graph of $\frac{1}{I}$ on the $y$ -axis against $R$ on the $x$ -axis.

(ii)

Draw the straight line of best fit.

(iii)

Determine the gradient and $y$ -intercept of this line.

gradient = ______

$y$ -intercept = ______

(d)

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

\frac{1}{I} = \frac{R}{E} + \frac{X}{E}

where $E$ is the electromotive force (e.m.f.) of the power supply and $X$ is the resistance of resistor X.

Using your answers to (c)(iii), determine values for $E$ and $X$ .
Give appropriate units.

$E$ = ______

$X$ = ______

1 more questions

Q2Manipulation, Measurement and Observation · Presentation of Data and Observations · Analysis, Conclusions and Evaluation20M

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