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
An engine operating between the boiling and freezing points of water will have
A. efficiency more than 27%.
B. efficiency less than the efficiency of a Carnot engine operating between the same two temperatures.
C. efficiency equal to $$27 \%$$
D. efficiency less than $$27 \%$$
Choose the correct answer from the options given below: