DP Physics (last assessment 2024)

Question 17N.3.SL.TZ0.2a

Date	November 2017	Marks available	[Maximum mark: 2]	Reference code	17N.3.SL.TZ0.2a
Level	SL	Paper	3	Time zone	TZ0
Command term	Show that	Question number	a	Adapted from	N/A

[Maximum mark: 2]

17N.3.SL.TZ0.2a

An electrical circuit is used during an experiment to measure the current I in a variable resistor of resistance R. The emf of the cell is e and the cell has an internal resistance r.

A graph shows the variation of $\frac{1}{I}$ with R.

(a)

Show that the gradient of the graph is equal to $\frac{1}{e}$ .

[2]

Markscheme

«ε = IR + Ir»

$\frac{1}{I} = \frac{R}{\varepsilon } + \frac{r}{\varepsilon }$