Question

Question 35
Find out the following in the electric circuit given in the figure.

(a) Effective resistance of two 8 $\Omega$ resistors in the combination
(b) Current flowing through 4 $\Omega$ resistors
(c) Potential difference across 4 $\Omega$ resistances
(d) Power dissipated in 4 $\Omega$ resistors
(e) Difference in ammeter readings, if any

Answer 1

(a) Effective resistance of the resistors connected in parallel is given by,
$\frac{1}{R}=\frac{1}{R_1}+\frac{1}{R_2}$
$\frac{1}{R}=\frac{1}{8}+\frac{1}{8}$
$R=\frac{R_1\times R_2}{R_1+R_2}$
$R=\left(\frac{8\times 8}{8+8}\right)=4\Omega$

(b) Total resistance = 4+4 = $8\Omega$
$I=\frac{V}{R}=\frac{8}{8}=1A$

(c) Potential drop = IR = 1 $\times$ 4 = 4V

(d) Power dissipated $=I^{2}R=(1{)}^{2}4=4W$

(e) The same current flows through each element in a series circuit. Therefore, there is no difference.