Force acting on a particle moving in a straight line varies with the velocity of the particle as $F = \frac{K}{v}$. Here $K$ is a constant. The work done by this force in time $t$ is

An electron moves with speed $2 \times 10^5 \ m/s$ along the positive $x$-direction in the presence of a magnetic field of induction $B = (\hat{i} + 4\hat{j} - 3\hat{k}) \ T$. The magnitude of the force experienced by the electron in newtons is (Charge on the electron $= 1.6 \times 10^{-19} \ C$)

If $\left[\begin{array}{rrr}1 & -1 & x \\ 1 & x & 1 \\ x & -1 & 1\end{array}\right]$ has no inverse,then the real value of $x$ is

Which of the following is not a greenhouse gas?

Which facilities have made poultry farming a popular business?

If the charge on the capacitor is increased by $2 \ C$,the energy stored in it increases by $21 \%$. The original charge on the capacitor is: (in $C$)