Question

In these three circuits all the batteries are identical and have negligible internal resistance, and all the light bulbs are identical. Rank all $5$ light bulbs ($A,B,C,D,E$) in order of brightness from brightness to dimmest

• A. $A=B=C>D=E$
• B. $A>B=C>D=E$
• C. $A=D=E>B=C$
• D. $A=D=E>B>C$

Answer 1

The correct option is C $A=D=E>B=C$

Image -1

$current=\frac{V}{R}$

Image-2

current in B=Current in C

$current=\frac{V}{2R}$

Image-3

current in D=current in E

$current=\frac{2V}{R}$

but current in each branch will

be $\frac{V}{R}$

So order of brightness:-

$A=0=E>B=C$