Light is incident normally on a completely absorbing surface with an energy flux of 25 W cm^–2. If the surface has an area of 25 cm², the momentum transferred to the surface in 40 min time duration will be :

The electric field of a plane electromagnetic wave is given by
$$\overrightarrow E = {E_0}\widehat i\cos (kz)cos(\omega t)$$
The corresponding magnetic field $$\overrightarrow B $$ is then given by

50 W/m² energy density of sunlight is normally incident on the surface of a solar panel. Some part of incident energy (25%) is reflected from the surface and the rest is absorbed. The force exerted on 1m² surface area will be close to (c = 3 × 108 m/s) :-

The magnetic field of a plane electromagnetic wave is given by :
$$$\overline B = {B_0}\widehat i\left[ {\cos (kz - \omega t)} \right] + {B_i}\widehat j\cos (kz + \omega t)$$$ B₀ = 3 × 10^–5 T and B1 = 2 × 10^–6 T.
The rms value of the force experienced by a stationary charge Q = 10^–4 C at z = 0 is closest to :