If all interior angles of a quadrilateral are in $AP$ and the common difference is $10^{\circ}$,then find the smallest angle in degrees.

If the sum of the deviations of $50$ observations from $30$ is $50$,then the mean of these observations is

Two concentric coils each of radius equal to $2\pi \, cm$ are placed at right angles to each other. $3\, A$ and $4\, A$ are the currents flowing in each coil respectively. The magnetic induction in $Wb/m^2$ at the centre of the coils will be $(\mu_0 = 4\pi \times 10^{-7} \, Wb/A \cdot m)$.

If $(2, 0)$ is the vertex and the $y$-axis is the directrix of a parabola,then its focus is

If $z = \sec(y - ax) + \tan(y + ax)$,then $\frac{\partial^2 z}{\partial x^2} - a^2 \frac{\partial^2 z}{\partial y^2}$ is equal to

An electric field of $1500\, V/m$ and a magnetic field of $0.40\, Wb/m^2$ act on a moving electron. The minimum uniform speed along a straight line the electron could have is: