Question
When the switch $$S,$$ in the circuit shown, is closed then the valued of current $$i$$ will be :
When the switch $$S,$$ in the circuit shown, is closed then the valued of current $$i$$ will be :
A.
$$3A$$
B.
$$5A$$
C.
$$4A$$
D.
$$2A$$
Answer :
$$5A$$
Solution :
Let voltage at $$C = x$$ volt
From kirchhoff’s current law,
$$KCL : {i_1} + {i_2} = i$$
$$\eqalign{ & \frac{{20 - x}}{2} + \frac{{10 - x}}{4} = \frac{{x - 0}}{2} \Rightarrow x = 10 \cr & \therefore i = \frac{V}{R} = \frac{x}{R} = \frac{{10}}{2} = 5A \cr} $$
Let voltage at $$C = x$$ volt
From kirchhoff’s current law,
$$KCL : {i_1} + {i_2} = i$$
$$\eqalign{ & \frac{{20 - x}}{2} + \frac{{10 - x}}{4} = \frac{{x - 0}}{2} \Rightarrow x = 10 \cr & \therefore i = \frac{V}{R} = \frac{x}{R} = \frac{{10}}{2} = 5A \cr} $$
