Engineering Questions with Answers - Multiple Choice Questions
Engineering Physics MCQ’s – Nuclear Fusion
Nuclear fusion is the phenomenon of ___________
a) Heavy nucleus splitting
b) Heavy nuclei combining
c) Light nucleus splitting
d) Light nuclei combining
Explanation: Nuclear fusion is the process in which two or more lighter nuclei fuse together to form a single stable and heavy nucleus.
The fusion reaction takes place under ________
a) High Temperature and Low Pressure
b) Low Temperature and High Pressure
c) High Temperature and High Pressure
d) Low Temperature and Low Pressure
Explanation: The fusion reaction takes place under the conditions of extremely high temperature (≈ 107 K) and pressure. This is necessary so that the protons have high enough Kinetic Energy to overcome their mutual repulsion.
Which process happens inside a star?
a) Electron Excitation
b) Nuclear fusion
c) Nuclear fission
Explanation: Throughout their lives, the stars undergo Nuclear fusion. Hydrogen and helium atoms fuse together to forge heavier elements.
The two types of cycles proposed in the stars for fusion are ________
a) p-p cycle and p-e cycle
b) p-p cycle and C-N cycle
c) p-p cycle and p-C cycle
d) p-p cycle and p-N cycle
Explanation: The two types of thermonuclear reactions that have been proposed into the stars for fusion are the Proton (p-p) cycle and the Carbon-Nitrogen (C-N) cycle.
In the Proton cycle, the hydrogen and deuteron fuse to form ___________
c) Helium – 3
d) Helium – 4
Explanation: The process is as follows: 2D + 1H -> 3He + Q X 2
The deuteron combines with a proton to yield Helium-3.
In the Carbon-Nitrogen cycle, nitrogen acts as a nuclear catalyst.
Explanation: In this cycle, carbon acts as a nuclear catalyst. The nitrogen is used as a reactant in the reaction and even a radioactive isotope of Nitrogen is formed.
The Q-value for both, the p-p cycle and the C-N cycle is same.
Explanation: The Q-value for both the cycles turns out to be 26.7 MeV. Both the p-p cycle and the C-N cycle’s net reaction is that four hydrogen atoms fuse together to form a helium atom and 26.7 MeV of energy.
What would be the effect of a nuclear holocaust?
a) Nuclear Summer
b) Nuclear Spring
c) Nuclear Autumn
d) Nuclear Winter
Explanation: It is predicted that in the event of a nuclear holocaust, the radioactive waste will hang like a cloud in the earth’s atmosphere. It will absorb the sun’s radiation resulting in a nuclear winter.
The unit used to measure the dose of radiation is ____________
Explanation: The unit used to measure the dose of radiation is roentgen. A single dose of one roentgen is defined to be the radiation that produces 1.6 X 1012 pairs of ions in 1 gm of air.
What should be the product of this fusion reaction?
a) Helium – 3
b) Helium – 4
c) Helium – 5
Explanation: The given figure can be expressed as the equation:
2H + 3H -> X + 1n, where X is the desired product.
As we know, the sum of mass numbers of reactants is equal to the mass number of the product. Therefore, the mass number of X should be 4.
Thus, it should be a Helium-4 ion.