Question

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

Answer 1

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

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