Question

Three resistors of resistance R1 R2 and R3 are connected 1.in series and then 2. Parallel. Write expressions of equivalent resistance of the combination in each case

Answer 1

answer is in the photo

Answer 2

Answer:

As given in question, there are three resistors namely $R_1$, $R_2$ and $R_3$. We have to calculate the expression of equivalent resistance when the resistors are connected in series and in parallel.

case 1: when resistors are connected in series

Let the equivalent resistance is R

then,

$R\ =\ R_1\ +\ R_2\ +\ R_3$

case 2: when resistors are connected in parallel

Let the equivalent resistance in parallel connection is R.

Then,

$\dfrac{1}{R}\ =\ \dfrac{1}{R_1}\ +\ \dfrac{1}{R_2}\ +\ \dfrac{1}{R_3}$