Question

An inductor of $20H$ and a resistance of $10\Omega$ , are connected to a battery of $5$ volt in series , then initial rate of charge of current is :

• A. $0.5amp/s$
• B. $2.0amp/s$
• C. $2.5amp/s$
• D. $0.25amp/s$

Answer 1

The correct option is D $0.25amp/s$

$L=20H$

$R=10\Omega$

$Voltage=5Volt$

$i\left(t\right)=\frac{V}{R}[1-e^{-\frac{RT}{L}}]$

$\frac{di\left(t\right)}{dt}|t=0=\frac{R}{L}\frac{V}{R}[1-e^{-\frac{RT}{L}}]$

$\frac{1}{2}\times \frac{5}{10}{e}^0$

$=\frac{1}{4}⟹0.25Amp/s$