Radioactivity: MCQ Test (25 questions)

Question 1 of 25

Graphite is used in nuclear reactors.

Alike fuel
Blike a lubricant
Cdiluent-like
Dnone of the above

Question 2 of 25

What is the unit of radioactivity?

AAngstrom
BCandela
CFermi
DCurie

Question 3 of 25

What type of charge do β-rays carry?

Apositive
Bnegative
CZero charge
DNone of these

Question 4 of 25

If the amount of a radioactive substance is doubled, then the rate of radioactive decay-

Aremains unchanged
Bhalf remains
Cincreases by √2 times
Ddoubles up

Question 5 of 25

Which of the following radioactive rays is equivalent to a helium nucleus?

Aalpha rays
Bbeta rays
CGamma rays
DNone of these

Question 6 of 25

The half-life of a radioactive substance is 4 months. The time required for three-quarters of this substance to decay is

Amonths
B4 month
C8 months
D12 months

Question 7 of 25

Which of the following radioelements is used to measure the speed of blood flow in the human body?

Aradio-phosphorus
Bradioiodine
CRadio-iron
DRadio-sodium

Question 8 of 25

What is the analog of electron?

Aα-particles
Bβ-particles
Cγ-particles
DH-atom

Question 9 of 25

What do radioactive elements emit?

Aultraviolet rays
Bα, β and γ radiation
Cradio waves
Dinfrared waves

Question 10 of 25

Who discovered 'radioactivity'?

ARutherford
BHenri Becquerel
CRoentgen
DEinstein

Question 11 of 25

Radioactivity is a property of what?

Aof electrons
Bof protons
Cof neutrons
Dof the nucleus

Question 12 of 25

Which particle is needed to continue the continuous process of uranium fission?

Aelectron
BProton
CNeutron
DPositron

Question 13 of 25

'Who invented the atomic bomb?

AMadame Curie
BPierre Curie
CAuto Han
DAlbert Einstein

Question 14 of 25

Which of the following rays has the lowest ionizing power?

Aof α-rays
Bof β-rays
Cof γ-rays
DNone of these

Question 15 of 25

How is the age of the Earth estimated?

AFrom uranium dating
Bfrom carbon dating
Cfrom the atomic clock
Dfrom the biological clock

Question 16 of 25

In what order are the penetrating powers of α, β and γ in their descending order

Aα, β, γ
Bγ, β, α
Cβ, α, γ
Dγ, α, β

Question 17 of 25

Beta rays have greater penetrating power than alpha rays of the same energy because-

Aβ-rays are made up of negatively charged electrons
Bβ-rays have a high velocity because their mass is negligible.
Cα-rays are positively charged and have a charge of 2 units.
Dβ-rays are repelled by the electron cloud, while α-rays are attracted.

Question 18 of 25

The substance formed after 1 β emission from Na²² is-

AMg
BMn
CAg
DPb

Question 19 of 25

Who first used the term 'radioactivity'?

AHenri Becquerel
BMarie Curie
CRutherford
DDe Broglie

Question 20 of 25

What is the system called that uses radioactivity to determine the age of prehistoric materials?

ARadium dating
BUranium dating
Ccarbon dating
DDeuterium dating

Question 21 of 25

Which scientist discovered gamma rays?

APaul Willard
BRutherford
CRoentgen
DDalton

Question 22 of 25

The emission of which of the following increases the atomic number of an element by one?

Aalpha particles
Bbeta particles
CProton
DNeutron

Question 23 of 25

If the half-life period of a radioactive substance is one day, then what fraction of its initial quantity will remain after 4 days?

A12.5%
B26.5%
C6.5%
D16.5%

Question 24 of 25

What are γ-rays made of?

Ameson particle
Bneutrino particle
CHiggs boson
Delectromagnetic waves

Question 25 of 25

Which of the radiations emitted from the nucleus has the highest penetrating power?

Aof alpha rays
Bof beta rays
Cof gamma rays
Dnone of these