Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Current Electricity

Question:

Current through wire XY of circuit shown is

Options:

1 A

4 A

2 A

3 A

Correct Answer:

2 A

Explanation:

Let current through XY is i3. Applying Kirchhoff’s law to loop (1) and (2),

$i_1+0 \times i_3-3 i_2=0$

∴   $i_1=3 i_2$                                  (i)

and  $-2\left(i_1-i_3\right)+4\left(i_2+i_3\right)=0$

So,   $2 i_1-4 i_2=6 i_3$                 (ii)

Also, $50=1i_1-2\left(i_1-i_3\right)$

$50=i_1-2\left(i_1-i_3\right)$

∴   $3 i_1-2 i_3=50$                     (iii)

From eqs. (i), (ii) and (iii), we get

$i_3=2 A$