The slow leakage of air from a very small hole in a container is an example of:

Q. Two identical pith balls, each of mass $m$ and carrying identical charges $q$ each, are suspended from a common point by two strings of equal length $l$. The angle between the string is $2\theta$, and initially changes at a rage $\left|\frac{d\theta }{dt}\right|={\omega }_0$, due to leakage of charge at a very slow rate. Find the rate of leakage of charge (i.e.$\left|\frac{dq}{dt}\right|$).

Q. Both crabs and lobsters are the members of Pleocyemata. Both possess a tail but in the crab, it is very small and not used. This is an example of

Q. ‘X’ is an example of a very old viable seed excavated from Arctic tundra. ‘X’ is

Q. A light is travelling from air into a medium. Velocity of light in a medium is reduced to $0.75$ times the velocity in air. Assume that angle of incidence '$i$' is very small, the deviation of the ray is

Q. _______ gas is present in air in a very small quantity and is important for plants.