Pick out the wrong statement?

Related Mcqs:

1. Pick out the wrong statement?

   A. α-particle emission from a radioactive element makes it electrically negative
   B. β-particle emission from a radioactive element makes it electrically positive
   C. A radioactive element having a half life period of 20 years will completely disintegrated in 40 years
   D. The disintegration constant of a radioactive isotope is independent of pressure, temperature or concentration

2. Pick out the wrong statement?

   A. Atoms with same number of nucleons but different number of protons are called isobars
   B. Atoms with same number of protons but different number of nucleons are called isoters
   C. Out of α, β, and γ-rays, the one having maximum penetration power are γ-rays
   D. The product formed by emission of α-particle has mass number less by 4 units than the parent nuclide

3. Pick out the wrong statement?

   A. The nucleus of a hydrogen atom is identical with a proton
   B. A, β-ray particle is identical with an electron
   C. Mass of an electron is about 1/1800th of the lightest nucleus
   D. Positron is heavier than a proton

4. Pick out the wrong statement?

   A. The ratio of the density of the ‘nucleus’ to that of the ‘atom’ is 1012
   B. α-particle is identical with a doubly charged helium ion
   C. The mass of deuterium atom is half that of helium atom
   D. Gamma rays are high energy electrons

5. Pick out the correct statement?

   A. Positron is the antiparticle of electron
   B. In α-decay, the ratio of neutron to proton decreases
   C. Ionising power of β-rays is higher than that of α-rays
   D. Speed of α-rays is more than that of γ-rays

6. Pick out the correct statement?

   A. Loss of electrons from neutral atoms produces negative ions
   B. The radius of nucleus & atomic size are of the order of 10-12 cm & 10-8 cm respectively
   C. Gain of electrons by neutral atoms form cations
   D. Proton to neutron ratio in a stable nucleus is 2 : 1

7. The half life period of a radioactive substance is best determined by counting the number of alpha particles emitted per second in a Geiger Muller counter from its known quantity. If the half life period of a radioactive substance is one month, then____________?

   A. 3/4th of it will disintegrate in two months
   B. It will completely disintegrate in two months
   C. It will completely disintegrate in four months
   D. 1/8th of it will remain intact at the end of four months

8. The phenomenon of radioactivity was discovered by___________________?

   A. Madam Curie
   B. Becquerel
   C. Roentgen
   D. J.J. Thomson

9. The velocity of thermal (slow) neutrons triggering nuclear fission reaction (having energy equal to 0.025 eV) is about ______________ metres/second?

   A. 1100
   B. 2200
   C. 3300
   D. 4400

10. Which is not a fissile nuclear material ?

    A. U-233
    B. U-235
    C. U-238
    D. Pu-239