Data Entry - Physics

If the lines $4x + 3y - 1 = 0$,$x - y + 5 = 0$,and $kx + 5y - 3 = 0$ are concurrent,then $k$ is equal to:

On a temperature scale $Y$,water freezes at $-160^{\circ} Y$ and boils at $-50^{\circ} Y$. On this $Y$ scale,a temperature of $340 \ K$ is (in $^{\circ} Y$)

The four arithmetic means between $3$ and $23$ are

The line among the following which touches the parabola $y^2=4ax$ is

$A$ spherical rubber balloon carries a charge,uniformly distributed over the surface. As the balloon is blown up and increases in size,the total electric flux coming out of the surface