The approximately nuclear radii ratio of the gold isotope ${}_{79}{}^{197}Au$ and the silver isotope ${}_{47}{}^{107}Ag$ is:

1. 1:1.23
2. 1:1.32
3. 1.01:1
4. 1.22:1

A 1000 MW fission reactor consumes half of its fuel in 5.00 yr. How much ${}_{92}{}^{235}U$ did it contain initially? Assume that the reactor operates 80% of the time, that all the energy generated arises from the fission of, ${}_{92}{}^{235}U$ and that this nuclide is consumed only by the fission process.

1. 4386 kg.
2. 3076 kg.
3. 4772 kg.
4. 8799 kg.

Suppose India had a target of producing by 2020 AD, 200,000 MW of electric power, ten percent of which was to be obtained from nuclear power plants. Suppose we are given that, on average, the efficiency of utilization (i.e. conversion to electric energy) of thermal energy produced in a reactor was 25%. How much amount of fissionable uranium would our country need per year by 2020? Take the heat energy per fission of ${}_{}{}^{235}U$ to be about 200MeV.
1. \(5.041 \times 10^4 \mathrm{~kg}.\)
2. \(2.074 \times 10^4 \mathrm{~kg}.\)
3. \(3.076 \times 10^4 \mathrm{~kg}.\)
4. \(4.026 \times 10^4 \mathrm{~kg}.\)