A current of 3 A enters one vertex P of an equilateral triangle PQR having three resistors of $1 \Omega$ each forming the sides of the equilateral triangle as shown. The value of $i_2$ in amperes is:

Current in a conductor is expressed as $I=8 t^3+3 t^2+2$, where current I is measured in amperes and time t is measured in seconds. What is the charge that flows through a cross-section of the conductor between time $t=1 \mathrm{~s}$ to $t=2 \mathrm{~s}$ ?

In the given circuit, an ideal voltmeter connected across $6 \Omega$ reads 5 V . The internal resistance $r$ of each cell is:

A galvanometer having a resistance of $50 \Omega$ is shunted by a wire of resistance $10 \Omega$. If the total current is 2 A , the current passing through the shunt is: