Insolation refers to the incoming solar power intercepted by the earth. Sunlight falls almost vertically on the equator, whereas it falls at some angles on the poles. So amount of insolation decreases from equator towards poles.
Since the positively charged particle (alpha-particle) projected towards west, so the direction of current is towards west. Now the deflection is towards north, so the force is towards north' Now...
(d) Insolation is the measure of solar radiation energy recieved on a given surface area in a given time. Some of the solar radiation is absorbed and the rest is...
