The energy required to knock out the electron in the third orbit of a hydrogen atom is equal to

The energy levels of the hydrogen spectrum is shown in figure. There are some transitions A, B, C, D and E. Transition A, B and C respectively represent

In the Bohr's hydrogen atom model, the radius of the stationary orbit is directly proportional to (n = principle quantum number)

If the potential difference between the anode and cathode of the X-ray tube is increases

Two large parallel plates are connected with the terminal of 100 V power supply. These plates have a fine hole at the centre. An electron having energy 200 eV is so directed that it passes through the holes. When it comes out it's de-Broglie wavelength is

Light of wavelength 2475 Å is incident on barium. Photoelectrons emitted describe a circle of radius 100 cm by a magnetic field of flux density Tesla. Work function of the barium is (Given

If a voltage applied to an X-ray tube is increased to 1.5 times the minimum wavelength of an X-ray continuous spectrum shifts by . The initial voltage applied to the tube is

The figure shows different graphs between stopping potential and frequency (n) for photosensitive surface of cesium, potassium, sodium and lithium. The plots are parallel. Correct ranking of the targets according to their work function greatest first will be

f(x) = is continuous at x = 2 then k =

is continuous on

The value of f (0) so that f(x) = is continuous at x = 0 is

We have to be careful that denominator is not zero. We have to readjust the function in a way we will not get zero at denominator for the function to be continuous at that point. And, we have to know different formulas of limit.

Ifthen atis

A point moves so that the ratio of its distances from two fixed points is constant Its Iocus is a

The points , , and are

The shortest distance of the point from on the ‐axis is equal to