Eamcet - Physics - Nuclear Physics

Particles and their anti-particles have

A.  The same masses but opposite spins

B.  The same masses but opposite magnetic moments

C.  The same masses and same magnetic moments

D.  Opposite spins and some magnetic moments

View Answer  

Correct Answer :

The same masses but opposite magnetic moments



Explanation :
No Explanation available for this question

A radioactive sample has half life of 5 days. To decay from 8 micro-curies to 1 micro-curie, the number of days taken will be :

A.  40

B.  25

C.  15

D.  10

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Correct Answer :

15



Explanation :
No Explanation available for this question

In Sun, the important source of energy is

A.  proton-proton cycle

B.  carbon-nitrogen cycle

C.  carbon-carbon cycle

D.  nitrogen-nitrogen cycle

View Answer  

Correct Answer :

proton-proton cycle



Explanation :
No Explanation available for this question

A proton, a deuteron (nucleus of 1H2) and an α-particle with same kinetic energy enter a region of uniform magnetic field moving at right angles to the field. The ratio of the radii of their circular  paths is :

A.  1 : 2 : 4

B.  1 : √2 : 1

C.  2 : √2 : 1

D.  1 : 1 : 2

View Answer  

Correct Answer :

1 : √2 : 1



Explanation :
No Explanation available for this question

A free neutron decays spontaneously into :

A.  a proton, an electron and anti-neutrino

B.  a proton, an electron and a-neutrino

C.  a proton and electron

D.  a proton, and electron, a neutrino and an anti-neutrino

View Answer  

Correct Answer :

a proton, an electron and anti-neutrino



Explanation :
No Explanation available for this question

The radioactivity of a sample is 'X' at a time 't1' and ‘Y’ at a time 't2'. If the mean life time of the specimen is г the number of atoms that have disintegrated in the time interval (t1 – t2) is

A.  Xt1 - Yt2

B.  X-Y

C.  X-Y / г

D.  (X -Y) г

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Correct Answer :

(X -Y) г



Explanation :
No Explanation available for this question

The half life of Ra226 is 1620 years. Then the number of atoms decay in one second in 1 gm of radium (Avogadro number = 6.023x1023)

A.  4.23x109

B.  3.16x1010

C.  3.61x1010

D.  2.16x1010

View Answer  

Correct Answer :

3.61x1010



Explanation :
No Explanation available for this question

To generate power of 3.2 MW, the number of fissions of U235 per minute is : (Energy released per fission =200 MeV; 1eV=1.6x10-19J)

A.  6 x 1018

B.  6 x 1017

C.  1017

D.  6 x 1016

View Answer  

Correct Answer :

6 x 1018



Explanation :
No Explanation available for this question