What is the gradient of any positive vector ?

Hopkinson's test on D.C. machines is conducted at

The best material to manufacture the core of a transformer is

The semiconductor diode that can be used in switching circuits in the microwave range is

Calculate the phase constant of a wave having a frequency of 5.4 GHz and travelling with a velocity of 2.75 x 10⁸ m/s.

Find the Cartesian coordinates of A = (9, 50°, 100°).

Stokes' theorem can be applied to which of the following?

Find the power of a wave in a cylindrical wave guide of radius 7 m and electric field of 49 V/m. Consider the medium to be air.

When a piece of copper and a piece of germanium are cooled from room temperature to 80K, the resistance of:

A charged oil drop is suspended in a uniform electric field of 3×10^4 V/m so that it neither falls nor rises. The charge on the drop (given the mass of the drop is 9.9×10^-15 kg and g=10 m/s^2) will be: