In a $dc$ motor,induced $e.m.f.$ will be maximum

$A$ spring of spring constant $5 \times 10^3 \, N/m$ is stretched initially by $5 \, cm$ from the unstretched position. Then the work required to stretch it further by another $5 \, cm$ is .............. $N-m$.

The solution set of $(5+4 \cos \theta)(2 \cos \theta+1)=0$ in the interval $[0, 2 \pi]$ is:

Which of the following is a valid mathematical statement?

Calculate the current (in $mA$) required to deposit $0.195 \ g$ of platinum metal in $5.0 \ hours$ from a solution of $[PtCl_6]^{2-}$ : (atomic weight: $Pt = 195$)

$A$ galvanometer of resistance $G$ is connected in a circuit. Now,a resistance $R$ is connected in series with the galvanometer. To keep the main current in the circuit unchanged,the resistance $S$ to be put in parallel with the series combination of $G$ and $R$ is: