Solar energy is due to:

Energy released in the fission of a single ${}_{92}U_{235}$ nucleus is 200 MeV. The fission rate of a ${}_{92}U_{235}$ filled reactor operating at a power level of 5 W is 

1. $1.56\times {10}^{-10}<mspace\; width="1em"></mspace>s^{-1}$ 

2. $1.56\times {10}^{11}<mspace\; width="1em"></mspace>s^{-1}$

3. $1.56\times {10}^{-16}<mspace\; width="1em"></mspace>s^{-1}$   

4. $1.56\times {10}^{-17}<mspace\; width="1em"></mspace>s^{-1}$

Which of the following is used as a moderator in nuclear reactors? 

1. Plutonium 

2. Cadmium 

3. Heavy water

4. Uranium 

Heavy water is used as a moderator in a nuclear reactor. The function of the moderator is 

1. to control energy released in the reactor

2. to absorb neutrons and stop the chain reaction

3. to cool the reactor

4. to slow down the neutrons to thermal energies

The power obtained in a reactor using \(\mathrm{U}^{235}\) disintegration is \(1000\) kW. The mass decay of \(\mathrm{U}^{235}\) per hour is:
1. \(1\) microgram
2. \(10\) microgram
3. \(20\) microgram
4. \(40\) microgram

Complete the equation for the following fission process-

$U_{92}^{235}+n_0^1\to S{r}_{38}^{90}+........$  

1. $X{e}_{{}_{54}}^{143}+3<mspace\; width="1em"></mspace>n_0^1$ 

2. $X{e_{{}_{54}}^{145}}^{}$

3. $X{e_{{}_{57}}^{142}}^{}$ 

4. $X{e_{{}_{54}}^{142}}^{}+n_0^1$

Fusion reaction takes place at high temperature because

1. atoms get ionised at high temperature 

2. kinetic energy is high enough to overcome the Coulomb repulsion between nuclei

3. molecules break up at high temperature

4. nuclei break up at high temperature

Atomic power station at Tarapore has a generating capacity of 200 MW. The energy generated in a day by this station is

(1) 200 MW               

(2) 200 J

(3) $4800\times {10}^6<mspace\; width="1em"></mspace>\mathrm{J}$          

(4) $1728\times {10}^{10}$ J

Fast neutrons can easily be slowed down by 

(1) The use of lead shielding

(2) Passing them through heavy water

(3) Elastic collisions with heavy nuclei

(4) Applying a strong electric field