Suppose a pure Si crystal has `5xx16^28` atoms. `m^(-3)`. It is doped by 1ppm concentraction of pentabalent As. Calculate the number of electron and holes. Given that `n_i=1.5xx10^16m^(-3)`.

Calculate the number of moles in 1m^3 of gas at N. T. P

Light enters from air to diamond which has refractive index of 2.42. Calculate the speed of light in diamond . The speed of light in air is 3.0 xx 10^8 m s^-1

For the reaction 2A harr 4B + C the concentration of B is increased by 5xx10^-3 mol L^-1 in 10 seconds. Calculate the rate of appearance of B.

For the reaction 2A harr 4B + C the concentration of B is increased by 5xx10^-3 mol L^-1 in 10 seconds. Calculate the rate of disappearance of A.

For a reaction 2A rarr 4B+C , the concentration of B is increased by 5.0xx10^(-3) molL^(-1) in 10 seconds. Calculate the rate of disappearance of A.

The work function of a metallic surface is 2.5 eV. Ultraviolet light of wavelength 2000Å is allowed to be incident on the metallic surface. Calculate Stopping potential. (Given Planck's constant h = 6.63 xx 10^(-34) J-s , electronic charge e = 1.6 xx 10^(-19) C, electron mass m = 9.1 xx 10^( -31) kg

A soap buble is slowing enlarged from a radius of 0.01 m to 0.1 m. Calculate the work done in the process[S= 26xx10^-3 N/m].