In the given circuit, a charge of $+80\,\mu C$ is given to the upper plate of the $4\,\mu F$ capacitor. Then in the steady state, the charge on the upper plate of the $3\,\mu F$ capacitor is ..... $\mu C$.

The probability that a number selected at random from the set of numbers ${1, 2, 3, \ldots, 100}$ is a cube, is

Pure $Si$ at $500\, K$ has equal number of electron $(n_e)$ and hole $(n_h)$ concentrations of $1.5 \times 10^{16} \,m^{-3}$. Doping by indium increases $n_h$ to $4.5 \times 10^{22} \,m^{-3}$. The doped semiconductor is of

Four resistors $A, B, C$ and $D$ form a Wheatstone bridge as shown in the figure. The bridge is balanced when $C = 100 \Omega$. If $A$ and $B$ are interchanged,the bridge balances for $C = 121 \Omega$. The value of $D$ is (in $\Omega$)

The packing efficiency of the two-dimensional square unit cell shown below is ........... $ \% $