Question

The equivalent resistance between (a) & (b) in the circuit can be obtained by the expression:

• A. $\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+\frac{1}{R_4}$
• B. $\frac{1}{R_{eq}}=\frac{1}{R_1}-\frac{1}{R_2}-\frac{1}{R_3}-\frac{1}{R_4}$
• C. $R_{eq}=R_1+R_2+R_3+R_4$
• D. $R_{eq}=R_1-R_2-R_3-R_4$

Answer 1

The correct option is A

$\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+\frac{1}{R_4}$

In a parallel circuit, the voltage across each of the components is the same.
For parallel connection,
$\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+...+\frac{1}{R_n}$.
$\therefore$ Equivalent resistance between (a) & (b) is obtained by the expression,$\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}+\frac{1}{R_4}$.