Atoms Molecules Nuclei Electrons Photons Test Online

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

2. A radioactive substance decays to 1/16^th of its initial activity in 40 days. The half-life of the radioactive substance expressed in days is

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

4. Which one of the following has the highest neutrons ratio?

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

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

7. X-ray will not show the phenomenon of

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

9. In ₈₈Ra²²⁶ nucleus there are:

10. Consider the following nuclear reaction X²⁰⁰ → A¹¹⁰ + B⁹⁰ + Energy If the binding energy per nucleon for X, A and B are 7.4 MeV, and 8.2 MeV and 8.2 MeV respectively, the energy released will be:

11. 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

12. The reaction responsible for the production of light energy from the sun will be:

13. 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

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

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