171. In Wilson cloud chamber radiations become visible reflection light from?
A. Ions
B. Nuclear radiations
C. Droplets of fog
D. Glass window
172. The track formed in the Wilson cloud chamber due to alpha particles is?
A. Thin and broken line
B. Thick continuous line
C. Thick line track in random direction
D. None of above
173. The track formed the Wilson cloud chamber due to beta particles is?
A. Thin and broken line
B. Thick continuous line
C. Whole region exposed to radiations
D. None of above
174. The spontaneous emissions of radiations from heavy nucleus ( A > 83 ) is called?
A. Nuclear fission
B. Nuclear Fusion
C. Radioactivity
D. None of above
175. Alpha particles are?
A. Protons
B. Positrons
C. Negatively charged
D. Helium nuclei
176. When a nucleus emit an Alpha particles its charge number decreases by?
A. 3
B. 2
C. 6
D. 5
177. Beta particles are?
A. Protons
B. Electrons
C. Positrons
D. Neutrons
178. Beta particles, carries a charge?
A. 2e
B. +2e
C. -e
None of above
179. When a nucleus emits an alpha particle its atomic mass decreases by?
A. 2
B. 1
C. 4
D. 3
180. Gamma rays carries a charge?
A. -e
B. +e
C. No charge
D. None of above