Thursday, 27 December 2012

PHYSICS Chapter 21

                                PHYSICS CHAPTER 21 

 
  1. The charge on proton is :
    a. 1.67 x 10^-27C
    b. 1.6 x 10^-19C
    c. 1.6 x 10^19C
    d. 1.673 x 10^-27C

    Right answer = C
  2. The background radiation to which we are exposed on the average is ____ per year ?

    a. 2 Sv
    b. 4 Sv
    c. 2 mSv
    d. 2 mrem

    Right answer = C
  3.  Doses of ___ will cause radiation burns to the skin :

    a. 3 Sv
    b. 2 Sv
    c. 2 mSv
    d. 3 mSv

    Right answer = A
  4.  For Sun, The temperature of its core is about _____ degree centigrade and its surface temperature is about ____ degree centigrade :

    a. 10 million, 5 million
    b. 20 million, 5 million
    c. 5 million , 6000
    d. 20 million , 6000

    Right answer = D
  5. Which of the following don't experience strong nuclear force :

    a. hadrons
    b. proton
    c. baryons
    d. leptons

    Right answer = D
  6.  Half life of U-238 is :

    a. 4.5 x 10^6 years
    b. 4.5 x 10^8 years
    c. 4.5 x 10^9 years
    d. 4.5 x 10^4 years

    Right answer = C
  7.  Isotopes of Hydrogen are :

    a. 1
    b. 2
    c. 3
    d. 4

    Right answer = C
  8.  Neutron is Discovered by :

    a. Chadwick
    b. Rutherford
    c. Bohr
    d. Einstein

    Right answer = A
  9.  Atomic Bomb is an example of :

    a. Fission process
    b. Fusion process
    c. nuclear reactor
    d. chemical process

    Right answer = A
  10. For Some of the absorbed dose a-particles are ___ times more damaging than X-rays :

    a. 2
    b. 5
    c. 10
    d. 20

    Right answer = D
  11.  Unit of Radioactivity ' curie ' is equal to :

    a. 3.40 x 10^9 disintegration/second
    b. 3.70 x 10^10 disintegration/second
    c. 3.55 x 10^10 disintegration/second
    d. 7.30 x 10^10 disintegration/second

    Right answer = B
  12.  When Nucleus emits an alpha particle its mass number drops by :

    a. 1
    b. 2
    c. 4
    d. 8
    Right answer = C
  13. Which of the following is Best shield against gamma rays ?

    a. concrete
    b. heavy water
    c. ordinary water
    d. Lead

    Right answer = D
  14.  1 amu is equal to = ?

    a. 1.02 MeV
    b. 931 eV
    c. 931 MeV
    d. 13.6 eV

    Right answer = C
  15. If Energy of electromagnetic nuclear reactions is less than 0.51 MeV then the dominant process is :

    a. pair production
    b. compton's effect
    c. Photoelectric effect
    d. Both b and c

    Right answer = C
  16.  What %age of Original radioactive atoms left after five half lives :

    a. 3%
    b. 5%
    c. 10%
    d. 20%

    Right answer = A
  17.  in fast reactor , the type of uranium used is :

    a. U 235
    b. U 238
    c. U 234
    d. U 239
    Right answer = B
  18.  Energy liberated when one atom of U -235 undergoes fission reaction is about :

    a. 200 MeV
    b. 200 eV
    c. 300 MeV
    d. 300 eV

    Right answer = A
  19.  Strontium 90 is used as :

    a. beta particle source
    b. alpha particle source
    c. gamma rays source
    d. neutron source

    Right answer = A
  20.  Binding energy per nucleon is maximum for ?

    a. cadmium
    b. iron
    c. uranium
    d. lead

    Right answer = B
  21.  Most abundant isotope of neon is :

    a. Neon - 20
    b. Neon - 21
    c. Neon - 22
    d. Neon - 23

    Right answer = A
  22. Those Elements whose charge number Z is greater than ___ are unstable :

    A. 79
    B. 80
    C. 90
    D. 82

    Right answer = D
  23.  The Radioactive Decay constant has the same dimensions as that of :

    a. Frequency
    b. Time
    c. Planck's constant
    d. angular momentum

    Right answer = A
  24.  Dead time of GM counter is in the order of :

    a. 10^4 sec
    b. 10^-4 sec
    c. 10^-8 sec
    d. 10^-6 sec

    Right answer = B
  25.  An alpha particle falls through a potential difference of 50 volts. Energy acquired by it will be :

    a. 25 eV
    b. 50 eV
    c. 100 eV
    d. 200 eV

    Right answer = C
  26. Total Number of Protons in the Nucleus is called as :

    a. Atomic number
    b. Mass number
    c. electronic number
    d. Protonic number

    Right answer = A
  27.  Building blocks of protons and neutrons are called as :

    a. quarks
    b. baryons
    c. hadrons
    d. mesons

    Right answer = A
  28. Neutron and Protons are commonly called :

    a. graviton
    b. deutrons
    c. mesons
    d. nucleons

    Right answer = D
  29. An alpha particle ionizes a molecule or atom through :

    a. direct collision
    b. electrostatic attraction
    c. electrostatic repulsion
    d. none of these

    Right answer = B
  30.  One amu is equal to :

    a. 3.32 x 10^-24 kg
    b. 1.66 x 10^-24 kg
    c. 1.67 x 10^-27 kg
    d. 1.6606 x 10^-27 kg

    Right answer = D

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