If the ammeter in the given circuit reads 2 A , the resistance R is

Question

If the ammeter in the given circuit reads 2 A , the resistance R is (A)  1 Ω  (B)  2 Ω  (C)  3 Ω  (D)  4 Ω

Tardigrade Admin · Accepted Answer

Equivalent resistance of 3Ω and 6Ω R' =(3×6/3+6) (in parallel) R' =(3 × 6/3+6) (in parallel) =(18/9)=2Ω Total resistance =2+R (in series) i=(V/R); 2=(6/2+R) 2+R=3 ⇒ R=1 Ω

Q. If the ammeter in the given circuit reads $2 A$ , the resistance $R$ is

$1 Ω$

$2 Ω$

$3 Ω$

$4 Ω$

Equivalent resistance of $3Ω$ and $6Ω$
$R^{'} = \frac{3 \times 6}{3 + 6}$ (in parallel)
$R^{'} = \frac{3 \times 6}{3 + 6}$ (in parallel)
$= \frac{18}{9} = 2Ω$
Total resistance $= 2 + R$ (in series)
$i = \frac{V}{R}; 2 = \frac{6}{2 + R}$
$2 + R = 3$
$\Rightarrow R = 1 Ω$

Q. If the ammeter in the given circuit reads 2A , the resistance R is

1Ω

2Ω

3Ω

4Ω