A resistor is connected in series with an unknown resistor to a ideal source

PHYSICS · Single correct · A Level · Physics · Electricity · Electricity

Problem

2\,\text{k}\Omega

resistor is connected in series with an unknown resistor

R_x

to a

20\,\text{V}

ideal source. If the potential difference across

R_x

is required to be

5\,\text{V}

, the nearest integer value of

R_x

should be (a)

2\,\text{k}\Omega

(b)

500\,\Omega

(c)

667\,\Omega

(d)

8\,\text{k}\Omega