The equivalent resistance is 4.5 ohm then the value of R in the circui

1.	The equivalent resistance is 4.5 ohm then the value of R in the circuit is
Answer» Answer: EXPLANATION: The two resistances 3 OHM and 3 ohm are in PARALLEL. Equivalent resistance of two resistances connected in parallel is : $\frac{1}{R_{eq}} = \frac{1}{R_{1}} + \frac{1}{R_{2}}$ Hence $\frac{1}{R_{eq}}$ = ( $\frac{1}{3} + \frac{1}{3}$ ) = $\frac{2}{3}$ ∴ $R_{eq}$ = $\frac{3}{2}$ ohm = 1.5 ohm As given that equivalent resistance of the whole circuit is 4.5 ohm, ⇒ 1.5 + R = 4.5 ∴ R = 3 ohm Thanks !