Three resistors have values

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

Problem

R

kR

and

k^{2}R

(where

R

is a constant resistance and

k

is a positive real number). They are connected in series to an ideal cell providing a constant potential difference

V

. (i) Derive, in terms of

R

and

k

, an expression for the equivalent resistance

R_{\text{eq}}

of the combination. (ii) Hence obtain an expression for the current

I

flowing through the circuit. (iii) If

V = 18\,\text{V}

R = 2\,\Omega

and

k = 2

, calculate the heat produced in the resistor of value

k^{2}R

during

5\,\text{minutes}

. (Use the appropriate relation between heat, current, resistance and time.)