Unit of radioactivity is _____________

(a)

roentgen

(b)

curie

(c)

becquerel

(d)

all the above

_____________ aprons are used to protect us from gamma radiations

(a)

Lead oxide

(b)

Iron

(c)

Lead

(d)

Aluminium

Kamini reactor is located at __________

(a)

Kalpakkam

(b)

Koodankulam

(c)

Mumbai

(d)

Rajasthan

The control rod in a nuclear reactor is made of

(a)

uranium

(b)

cadmium

(c)

graphite

(d)

plutonium

Fusion reaction is initiated with the help of
(i) low temp
(ii) high temp
(iii) low press
(iv) high press

(a)

(i) is correct

(b)

(ii) & (iv) are correct

(c)

(i) & (iv) are correct

(d)

(ii) & (iv) are correct

A chain reaction is continuous due to

(a)

large mass defect

(b)

large energy

(c)

production of more neutrons in fission

(d)

None of these

Nucleons are made of ________.

(a)

atoms

(b)

electrons and protons

(c)

electrons and neutrons

(d)

protons and neutrons

૪ rays are ________ in charge.

(a)

positive

(b)

negative

(c)

neutral

(d)

none

Gamma - rays are ________ in nature.

(a)

gravitational

(b)

electromagnetic

(c)

weak

(d)

nuclear

Irene Curie and F. Joliot discovered __________in the year 1934.

(a)

natural radioactivity

(b)

fluorescence

(c)

artificial radioactivity

(d)

hydrogen bomb

Radio __________ is used in the treatment of skin diseases

(a)

iron

(b)

phosphorous

(c)

sodium

(d)

iodine

In molecular biology, radioisotope are used in ________ surgical instruments.

(a)

engraving

(b)

sterilizing

(c)

sharpening

(d)

preserving

U²³⁸ kept in nuclear reactors, generally decay into _________.

(a)

Np²³⁹

(b)

PU²³⁹

(c)

both (a) and (b)

(d)

U²³⁵

Chain reaction is possible, only if the size of system is __________ the critical size.

(a)

less than

(b)

greater than

(c)

equal to

(d)

independent of

U²³⁸ is fissionable _________ neutrons.

(a)

only by fast

(b)

only by slow

(c)

both fast and slow

(d)

by thermal

In order to supply neutrons for research purpose, we use ________ reactors.

(a)

research

(b)

power

(c)

production

(d)

source

A good ________ shows down neutrons by elastic collisions and it does not remove them by absorption.

(a)

fuel

(b)

moderator

(c)

coolant

(d)

control rod

Which of the following is not a moderator?

(a)

liquid sodium

(b)

ordinary water

(c)

graphite

(d)

heavy water

BARC is situated at ________.

(a)

Trombay

(b)

Kalpakkam

(c)

Trivandrum

(d)

Thumba

The mass of the product nucleus is always _______ the sum of masses of the lighter nuclei.

(a)

less than

(b)

greater than

(c)

equal to

(d)

the product of the product nucleus.