Question

A battery of four cells in series, each having an E.M.F. of $1.5V$ and internal resistance $1$$\Omega$ are connected in series with an ammeter, a coil of resistance $2$ $\Omega$ and a filament lamp. If the ammeter reads $0.5A$, the resistance of the filament lamp is

• A. 4$\Omega$
• B. 6$\Omega$
• C. 2$\Omega$
• D. 12$\Omega$

Answer 1

Answer: (B)

6$\Omega$

$\Rightarrow$ Given $I=0.5A$
$\Rightarrow 4E=I[4r+2+R]$
$4\times 1.5=0.5[4+2+R]$
$12=6+R$
$R=6\Omega$