Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

Assertion A : EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology.

Reason R : Infrared EM waves are more energetic than microwaves, (used in Radar)

In the light of given statements, choose the correct answer from the options given below.

In an n-p-n common emitter (CE) transistor the collector current changes from 5 $$\mathrm{mA}$$ to $$16 \mathrm{~mA}$$ for the change in base current from $$100~ \mu \mathrm{A}$$ and $$200 ~\mu \mathrm{A}$$, respectively. The current gain of transistor is __________.

The ratio of escape velocity of a planet to the escape velocity of earth will be:-

Given: Mass of the planet is 16 times mass of earth and radius of the planet is 4 times the radius of earth.

Two satellites $$\mathrm{A}$$ and $$\mathrm{B}$$ move round the earth in the same orbit. The mass of $$\mathrm{A}$$ is twice the mass of $$\mathrm{B}$$. The quantity which is same for the two satellites will be