1. Radioactivity is the fission of –
2. What is the unit of the physical quantity, Radio Activity?
3. Phenomenon of Radioactivity was discovered by –
4. Radioactive decay of Uranium resulted the formation of final product–
5. In India Nuclear Weapon was tested at –
(A) Shri Hari Kota
6. Radioactivity is Measured by –
(D) Geiger – Muller counter
7. Which one of the following is not a radioactive element?
8. The most suitable unit to express the nuclear radius is–
9. The electron emitted in beta radiation originates from–
(A) Inner orbits of atoms
(B) Free electrons existing in nuclei
(C) Decay of a neutron in a nuclei
(D) Photon escaping from the nucleus.
10. Which one of the following element does not show radioactivity?
11. Radioactive Noble Gas is–
(A) Xe (B) He
(C) Ne (D) Rn
12. There is no change in radioactive element (Mass or charge) during –
(A) Gamma emission
(C) Alpha emission
(D) Beta emission
13. Which of the following is a radioactive element?
14.Which one of the following is radioactive?
15. Which one of the following is not a radio-active element?
16. Radioactive samples are stored in lead boxes. Lead is used because it is:
(C) Good absorber
(D) Bad conductor
17. The nuclear forces are –
(A) Charge independent
(B) Spin independent
(C) Charge symmetric
(D) Long range.
18. The lightest radioactive element is
19. An element that does not occur in nature but can be produced artificially is
20. Which of the following is a radioactive element?
21. Radioactive elements emit:
(B) Infrared waves
(C) Ultraviolet waves
(D) , and radiations
22. Which of the following caused radioactive pollution along the coast of Kerala?
23. Which of the following elements is not radioactive?
24. Which of the following elements does not exhibit natural radioactivity?
25. The unstability of a nucleus is due to :
(A) Higher electron-to-proton ratio
(B) High neutron-to-proton ratio
(C) Low electron-to-proton ratio
(D) Low neutron-to-electron ratio.
26. Which of the following nuclei is unstable ?
27. A radioisotope will emit :
(A) -and -particles simultaneously.
(B) -and -rays simultaneously.
(C) -and -rays simultaneously
(D) -or -rays and then -rays.
28. Unstab le substances exh ib it higher radioactivity due to :
(A) Low p/n ratio
(B) High p/n ratio
(C) p/n = 1
(D) None of these
29. Which among the following is false about alphas particles ?
(A) They have high ionizing power
(B) They have high penetrating power
(C) They have high kinetic energy
(D) They are positively charged helium nuclei
30. Which type of reaction produces the most harmful radiation?
(C) Chemical reaction
(D) Photo Chemical
31. The element which is commonly used in nuclear reactor for producing electricity in nuclear fission is
32. High amount of energy is released in the explosion of atomic bomb is due to–
(A) Conversion of Mass into energy
(B) Conversion of Chemical Energy into thermal energy.
(C) Conversion of Mechanical energy into nuclear energy
(D) Conversion of neutrons into Protons
33. Nuclear Power Reactor acts on the Principle of–
(C) Thermal Heating
(D) Combined Effect of all three given above
34. Name the particle that is most essential to continue the chain reaction during the fission of Uranium-
35. Who Invented the nuclear reactor?
(A) Enrico Fermi
(B) Adolf Gaston Eugen Fick
(C) Sandford Fleming
(D) Benoit Fourneyron
36. The two elements which are used to absorb the neutrons in nuclear fission during chain reaction –
(A) Boron and Cadmium
(B) Boron and Plutonium
(C) Cadmium and Uranium
(D) Uranium and Boron
37. Graphite is used as a………… in nuclear reactors.
(D) Electric Insulator
38. Which one of the following used as a moderator in nuclear reactor?
(A) Uranium (B) Radium
(C) Thorium (D) Graphite
39. Heavy water used as a coolant in nuclear reactor. Heavy Water is:
(A) Water rich in Minerals
(B) Ozonised water
(C) Water containing Minerals of Heavy metals
(D) Water containing heavy Isotopes of Hydrogen atom
40. In nuclear reactor, Neutrons are slowdown by the–
(A) Fissionable Product
(C) Controlling rod
(D) Coolant system
41. Alpha particles are ___________.
(A) Twice the mass of beta particles
(B) Negatively charged
(C) Just like helium nuclei
(D) Lower in ionizing power as compared to gamma rays