An electron beam moving with a speed of 2x10⁷ms^-1 enters a magnetic field of induction 3x10^-3T, directed perpendicular to its direction of motion. The intensity of electric field applied so that the electron beam is undeflected due to the magnetic field is

An intrinsic semi conductor has 10¹⁸/m³ free electron and is doped with pentavalent impurity of 10²⁴/m³.Then the free electrons density order increases by

The wave length of the K_αline for an element of atomic number 43 is λ.Then the wavelength of the K_αline for an element of atomic number 29,is

When a monochromatic light of frequency v is incident on a metal, stopping potential is V₀. Frequency of the incident light for which stopping potential becomes 2V₀ is

in a half wave rectifier output is taken across a 90 ohm load resistor. If the resistance of diode in forward biased condition is 10 ohm, the efficiency o rectification of ac power into dc power is

The rate constant of the reaction at temperature 200K is 10 times than the rate constant at 400K.The activation energy of the reaction is

In a p-n junction the depletion region is 400nm wide and electric field of 5x10⁵Vm^-1 exists in it. The minimum energy of a conduction electron, which can diffuse from n-side to the p-side is

200MeV energy is released when one nucleus of ²³⁵U undergoes fission. The number of fissions per second required for producing a power of 1 megawatt

In an experiment of photoelectric emission, for incident light of 4000A⁰, stopping potential is 2V. If the wavelength of incident light is made 3000A⁰, then the stopping potential will be