A circuit consists of two fixed resistors of and connected in series with a variable…

PHYSICS · Multi-part · CBSE · Physics · Electricity · Electricity

Problem

A circuit consists of two fixed resistors of

3\,\Omega

and

9\,\Omega

connected in series with a variable resistor

R_{\text v}

that can be adjusted from

0\,\Omega

12\,\Omega

. The combination is connected across a

24\,\text{V}

battery of negligible internal resistance. (i) Write an expression for the total resistance

R_{\text{eq}}

of the circuit in terms of

R_{\text v}

. (ii) Determine the minimum and maximum values of

R_{\text{eq}}

R_{\text v}

is varied through its range. (iii) For each extreme value of

R_{\text{eq}}

, calculate the corresponding current drawn from the battery.