Atoms Molecules Nuclei Electrons Photons Test Online

1. Which one of the following is not dependent on the intensity of incident photon in a photo electric experiment?

2. A laser beam is used for carrying out surgery because it:

3. The function of heavy water in a nuclear reactor to

4. In the nuclear reaction, there is a conservation of:

5. The kinetic energy of an electron, which is accelerated in the potential difference of 100 V, is:

6. If the radioactive decay constant of radium is 1.07 x 10⁻⁴ per year. Then its half life period approximately is equal to:

7. In Bohr’s theory, relation between principal quantum number n and radius of orbit r is:

8. A proton is about 1840 times heavier than an electron. When it is accelerated by a potential difference of 1 kV, its kinetic energy will be

9. The speed of an electron having a wavelength of 10⁻¹⁰ m is:

10. Particle nature and wave nature of electromagnetic waves and electrons can be represented by:

11. In ₈₈Ra²²⁶ nucleus there are:

12. For an electron in the second orbit of hydrogen the moment of momentum as per Bohr’s model is

13. When radioactive substance emits an α-particle, then its position in the periodic table is lowered by:

14. The surface of zone material is radiated in turn by waves of λ = 350 nm and 540 nm respectively. The ratio of the stopping potential in the two cases is 2:1. The work function of the material is

15. Half life of a substance is 20 minutes and then the time between 33% decay and 67 % decay will be