1. Radioactivity was discovered in the year
(A) 1896
(B) 1938
(C) 1911
(D) 1913
2. Gamma rays can be stopped by
(A) 0.01 mm Al
(B) 1 cm Al
(C) Not by 6 cm Pb
(D) 3 cm Pb
3. Non-radioactive substance becomes radioactive on bombardment of proton or neutron
(A) Natural radioactivity
(B) Fission
(C) Artificial radioactivity
(D) None of these
4. Alpha rays can be blocked by placing Aluminum plate in their path
(A) 0.01 mm thick
(B) 0.1 mm thick
(C) 1.00 mm thick
(D) 100 mm thick
5. Atomic bomb is an example of
(A) Fission reaction
(B) Fusion reaction
(C) Endothermic
(D) All of these
6. Ice packed in an airtight stainless steel bottle is a type of system
(A) Open system
(B) Closed system
(C) Isolated system
(D) Isothermal system
7. Velocity of alpha rays is
(A) Equal to velocity of light
(B) 10 times that of velocity of light
(C) 1/10 of the velocity of light
(D) 100 times velocity of light
8. Thickness of Aluminum plate needed to stop alpha rays
(A) 1 cm
(B) 0.01 cm
(C) 0.1 cm
(D) 10 cm
9. Hydrogen bomb’s principal reaction is
(A) Fission
(B) Fusion
(C) Combustion
(D) All of these
10. The charge on alpha particle is
(A) +1
(B) +2
(C) −1
(D) Neutral