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A radioactive source of halflife 2 h emi...

A radioactive source of halflife 2 h emits radiation of intensity which is 64 times the permissible safe level. The minimum time in hours after which it would be possible to work safely with the source is:

A

12

B

8

C

6

D

24

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SARAS PUBLICATION-MODEL QUESTION PAPER 6-EXERCISE
  1. A radioactive source of halflife 2 h emits radiation of intensity whic...

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  2. Nuclear fusion is not found in:

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  3. a. Give the expression for the radius of a nucleus. b. What is the r...

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  4. Complete the diagram.

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  5. Acceptor level in p-type semiconductor lies:

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  6. The frequencies that are reflected are transmitted at ionospheric laye...

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  7. The gap between the frequency of the side bands in an amplitude modula...

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  8. A transmitting antenna at the top of a tower has a height 32 m and tha...

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  9. The wrong unit-conversion among the following is:

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  10. Choose the wrong statement

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  11. The displacement of a particle as a function of time is shown in figur...

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  12. The range of a projectile is R when the angle of projection is 30^@. F...

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  13. The scalar quantity among the following is:

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  14. Which one of the following motions on a smooth plane surface does not ...

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  15. Pick out the wrong statement :

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  16. Two bodies of masses 3m and 9m are moving with equal kinetic energies....

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  17. Two bodies of masses 1 kg and 2 kg moving with same velocities are sto...

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  18. If two circular discs A and B are of same mass but of radii r and 2r r...

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  19. Choose the wrong statement

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  20. Orbital velocity of earth satellite does not depend on:

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