Rutherford's experiment on scattering of $\alpha-$particles showed for the first time that the atom has

The heat energy absorbed by a system undergoing the cyclic process shown in the figure is:

An electron (mass = $9.1 \times 10^{-31} \ kg$; charge = $1.6 \times 10^{-19} \ C$) experiences no deflection if subjected to an electric field of $3.2 \times 10^5 \ V/m$ and a magnetic field of $2.0 \times 10^{-3} \ Wb/m^2$. Both the fields are normal to the path of the electron and to each other. If the electric field is removed,then the electron will revolve in an orbit of radius.......$m$

$A$ $2 \ m$ long rod of radius $1 \ cm$ which is fixed from one end is given a twist of $0.8 \ radians$. The shear strain developed will be

$A$ bag contains $2n+1$ coins. It is known that $n$ of these coins have a head on both sides,whereas the remaining $n+1$ coins are fair. $A$ coin is picked up at random from the bag and tossed. If the probability that the toss results in a head is $\frac{31}{42}$,then $n$ is equal to

If $y = \sin px$ and $y_n$ is the $n^{th}$ derivative of $y$,then $\left| \begin{array}{ccc} y & y_1 & y_2 \\ y_3 & y_4 & y_5 \\ y_6 & y_7 & y_8 \end{array} \right|$ is equal to