#### Nuclear Physics English Medium Free Online Test 1 Mark Questions with Answer Key 2020 - 2021

10th Standard

Reg.No. :
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Science

Time : 00:15:00 Hrs
Total Marks : 15

Part A

15 x 1 = 15
1. Unit of radioactivity is _____________

(a)

roentgen

(b)

curie

(c)

becquerel

(d)

all the above

2. _____________ aprons are used to protect us from gamma radiations

(a)

(b)

Iron

(c)

(d)

Aluminium

3. In the nuclear reaction 6X12 $\overset { \alpha decay }{ \longrightarrow }$ zYA the value of A & Z.

(a)

8, 6

(b)

8, 4

(c)

4, 8

(d)

cannot be determined with the given data

4. Which of the following is/are correct?
i. Chain reaction takes place in a nuclear reactor and an atomic bomb.
ii. The chain reaction in a nuclear reactor is controlled
iii. The chain reaction in a nuclear reactor is not controlled
iv. No chain reaction takes place in an atom bomb

(a)

(i) only correct

(b)

(i) & (ii) are correct

(c)

(iv) only correct

(d)

(iii) & (iv) are correct

5. The explosion of the atomic bomb takes place due to

(a)

Nuclear fission

(b)

Nuclear fusion

(c)

Scalteling

(d)

Heating

6. Fusion reaction takes place at high temp.

(a)

atoms are ionised

(b)

molecules break up

(c)

nuclei break up

(d)

to overcome repulsion between nuclei

7. Atomic nucleus was discovered by _______

(a)

Rutherford

(b)

Newton

(c)

Einstein

(d)

Nobel

8. Elements having atomic number greater than ________ are radioactive.

(a)

48

(b)

68

(c)

88

(d)

83

9. β-rays are nothing but _________.

(a)

protons

(b)

neutrons

(c)

electrons

(d)

helium

10. Radio ________ is used in the treatment of cancer.

(a)

sodium

(b)

cobalt

(c)

iron

(d)

phosphorous

11. Radio - carbon dating can be done with _________.

(a)

only living things

(b)

only non - living things

(c)

both (a) and (b)

(d)

none

12. Roentgen (R) is the unit to measure _________.

(a)

X - ray strength

(b)

number of holes produced by X - rays

(c)

(d)

number of cancer cells

13. Radioactive materials are kept -in thick -walled ________ containers.

(a)

aluminium

(b)

iron

(c)

brick

(d)

14. Minimum size of a system in which at least 1 neutron is available for further fission is called________.

(a)

cut - off size

(b)

critical size

(c)

range of reactor

(d)

capability criteria

15. Commonly used moderators are _________ and________.

(a)

D2O, H2O

(b)

D2, H2

(c)

O2, H2

(d)

O2,N2