Question

The magnitude of 'I' in ampere unit is

• A. 0.1
• B. 0.3
• C. 0.6
• D. None of these

Answer 1

The correct option is A 0.1

Applying Kirchoff's law in the following figure.
At junction A:
$I+I_1+I_2=1....\left(i\right)$
For loop (i)
$-60I+(15+5)I_1=0$
$\Rightarrow I_1=3I....\left(ii\right)$
For loop (2)
$-(15+5)I_1+10I_2=0$
$2I_1=I_2.....\left(iii\right)$

On solving equation (i),(ii) and (iii) we get $I=0.1A$
Short Trick: Branch current = main current $\left(\frac{Resistanceofoppositebranch}{Totalresistance}\right)$


$\Rightarrow I=1\times \left[\frac{\frac{20}{3}}{\frac{20}{3}+60}\right]$
=0.1 A