Embibe Experts Solutions for Chapter: Current Electricity, Exercise 4: Exercise (Previous Year Questions)

Charges $+q$ and $–q$ are placed at points $A$ and $B$ respectively which are a distance $2L$ apart, $C$ is the mid point of $A$ and $B$. The work done in moving a charge $+Q$ along the semicircle $CRD$ is :

A charged capacitor is connected with a resistor. After how many time constants, does the energy of capacitor becomes 1/10 th of its initial value ?

Given that the mobility of electron's in Ge is 0.4 metre square/volt sec and electronic charge is 1.6 x10^–19C . How many donor atom (per m³) have in semiconductor of conductivity 500 mho/m :-