Heavy water used in the nuclear reactors to slow down the speed of neutrons is

A first order reaction is to be treated in a series of two mixed reactors. The total volume of the two reactors is minimum, when the reactors are

A

Equal in size

B

Of different sizes

C

Of such size that the ratio of their volumes is

D

None of these

Gold is 19 times as heavy as water and Copper is 9 times as heavy as water. Calculate the ratio in which these two metals should be mixed so that the mixture is 15 times as heavy as water.

A

40

B

41

C

42

D

43

Where reactor operation is designed with fast neutrons such as in reactors using highly enriched fuel, the moderator used is

A

Heavy water

B

Graphite

C

Carbon dioxide

D

No moderator is needed

In order to have constant chain reaction to produce a constant rate of heat output, the value of ratio of the number of neutrons in one generation to the number of neutrons in the immediately preceding generation must be

A

Greater than 1.0

B

Less than 1.0

C

Equal to zero

D

Equal to 1.0

Gas cooling as compared to water cooling of nuclear reactors

A

Can not attain a high temperature

B

Is more efficient as gas has a higher specific heat

C

Can produce only saturated steam for feeding to power turbine

D

None of these

Which is the most commonly used molten metal for cooling of nuclear reactors?

A

Zinc

B

Sulphur

C

Sodium

D

Manganese

Nuclear fuel generally used in reactors is uranium oxide instead of uranium, because the former has higher

A

Melting point, hence can be subjected to higher temperature

B

Density ; hence core volume for a given power output would be smaller

C

Resistance to effects of irradiation

D

All of the above

The control rods in the control system of nuclear reactors are used to

A

Absorb excess neutrons

B

Control fuel consumption

C

Control temperature

D

All of these

Nuclear reactors are used

A

To produce heat for thermoelectric power

B

To produce fissionable material

C

To propel ships, submarines, aircrafts

D

All of these

Thermal shield is used in high powered nuclear reactors to

A

Protect the walls of the reactor from radiation damage

B

Absorb the fast neutrons

C

Slow down the secondary neutrons

D

Protect the fuel element from coming in contact with the coolant

Heavy water used in the nuclear reactors to slow down the speed of neutrons is

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