$A$ marble block of mass $2\, kg$ lying on ice when given a velocity of $6\, m/s$ is stopped by friction in $10\, s$. Then the coefficient of friction is-

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

Which of the following groups of algae do not have eukaryotic organization?

During the depression in freezing point experiment,an equilibrium is established between the molecules of

$A$ parallel plate capacitor is charged and then disconnected from the charging battery. If the plates are now moved farther apart by pulling at them by means of insulating handles, then

If $P=(0,1,2)$,$Q=(4,-2,1)$,and $O=(0,0,0)$,then $\angle POQ$ is equal to