3498. The ratio of neutrons to protons of an element having a mass number and atomic number of 80 and 40 respectively is
1
0.5
2
4
✅ The correct answer is option A.
3502. Which of the following is the most harmful for the human being ?
β-rays
X-rays
γ-rays
ultra violet rays
✅ The correct answer is option C.
3506. Which of the following isotopes is not present in natural uranium ?
U-238
U-234
U-235
U-232
✅ The correct answer is option D.
3508. A pressurised water reactor (PWR) uses pressurised water as a
coolant.
working fluid in power turbine.
moderator.
none of these.
✅ The correct answer is option A.
3515. A moderator __________ the neutrons.
slows down
absorbs
accelerates
reflects
✅ The correct answer is option A.
3520. Which of the following is not used as a moderator in nuclear reactor ?
Molten sodium
Light water
Beryllium
Boron hydride
✅ The correct answer is option A.
3489. An element having large number of __________ is most easily subjected to nuclear fission.
protons
electrons
neutrons
nucleons
✅ The correct answer is option D.
3494. Positron is a/an
nucleus having two protons.
helium nucleus.
electron with positive charge.
nucleus with one proton and one neutron.
✅ The correct answer is option C.
3499. Thorium-232 is converted into uranium-233 in a/an __________ nuclear reactor.
thermal
fast breeder
heavy water moderated
enriched uranium
✅ The correct answer is option B.
3454. Which of the following fuel gases will require maximum amount of air for combustion of 1 Nm³ gas ?
Blast furnace gas
Natural gas
Producer gas
Water gas
✅ The correct answer is option B.