Question

QUESTION 1

1. What is the approximate radius of an oxygen nucleus with 8 protons and 8 neutrons?

   	1.	3.02 fm
   	2.	2.4 fm
   	3.	3.53 fm
   	4.	1.10 fm
   	5.	2.89 fm

1 points   

QUESTION 2

1. It is possible to tell α particles from β particles by placing the decaying atom

   in a magnetic field because

   	1.	α particles deflect in the magnetic field but β particles don't
   	2.	β particles deflect in the magnetic field but α particles don't
   	3.	α particles deflect in one direction and β particles in other.
   	4.	α and β particles both deflect in the samedirection but β particles deflect much more.
   	5.	α and β particles both deflect in the same direction but α particles deflect much more.

1 points   

QUESTION 3

1. In terms of the penetrating capabilities of the different types of radiation

   	1.	they all penetrate roughy the same amount of material
   	2.	γ rays can penetrate much deeper than α rays
   	3.	α rays can penetrate much deeper than γ rays
   	4.	β rays can penetrate much deeper than γ rays

1 points   

QUESTION 4

1. Particles which are acted on by the weak nuclear force but not the strong nuclear force are

   referred to as

   	1.	quarks
   	2.	hadrons
   	3.	mesons
   	4.	baryons
   	5.	leptons

1 points   

QUESTION 5

1. When a kilogram of a material has absorbed 0.01 Joules of energy from radiation, we say

   it has received

   	1.	1 rad
   	2.	1 roentgen
   	3.	1 RBE
   	4.	1 curie

1 points   

QUESTION 6

1. Which of the following particles will have a larger biological effect on a human assuming they all

   have the same energy?

   	1.	an X-ray
   	2.	a γ ray
   	3.	a slow neutron
   	4.	an α particle

1 points   

QUESTION 7

1. The purpose of the control rods in a nuclear reactor is to

   	1.	slow down the neutrons given off during fission
   	2.	speed up the neutrons given off during fission
   	3.	absorb the neutrons given off during fission
   	4.	absorb the protons given off during fission
   	5.	absorb the γ rays given off during fission

1 points   

QUESTION 8

1. The purpose of a moderator in a nuclear reactor is to

   	1.	slow down the neutrons given off during fission
   	2.	speed up the neutrons given off during fission
   	3.	absorb the neutrons given off during fission
   	4.	absorb the protons given off during fission
   	5.	absorb the γ rays given off during fission

1 points   

QUESTION 9

1. Which of the four fundamental forces has the largest interaction strength?

   	1.	gravitational force
   	2.	weak nuclear force
   	3.	strong nuclear force
   	4.	electro-magnetic force

1 points   

QUESTION 10

1. It is possible to imagine the human body by looking at the radiation produced from

   the annihilation of matter and antimatter. This is referred to as

   	1.	magnetic resonance imaging (MRI)
   	2.	X-rays
   	3.	computer aided tomography (CAT)
   	4.	positron emission tomography (PET)

1 points   

Answer 1

1) Radius of nucleus R=R₀A^1/3. where R₀=1.4×10^-15m

so for oxygen A=16. radius is = 1.4×(16)^1/3 fm = 3.53 fm

so option 3

2) Alpha particle have positively charged and Beta particle have negatively charge so they both deflect in magnetic field but in opposite direction. option 3

3) penetration power of y rays are more than alpha & beta decay.

4) Quarks and leptons both are half spin particles . they show weak interction force. but Leptons are shows much less weak intrection.

5) the unit of absorb radiation 1 j/kg = 100rad

so. 0.01 j/kg = 1 rad. option 1

6) Ionising ability affect the human body tissues

alpha have very small absorption range

Betarays are harmful for DNA

gamma rays are more Cantonese then alpha and beta

neutron radiation is strongest post of penetration it most Cantonese from other

X-ray radiation affect body if body is continuously in x-ray zone.

7) Basically graphite rods are used for absorb the neutrons to stop further reaction.

8) A moderator is a material used in radiated to slow down the neutrons.

9) strong nuclear force has largest infraction strength. but gravitational force have largest range but not strongest .

10) Positron emission tomography use annihilation of matter to emit the positrons.