Nuclear (Physics) Part-I

Total Questions: 50

1. Which one of the following pairs is not correctly matched: [U.P.U.D.A./L.D.A. (Pre) 2002, U.P.P.C.S. (Pre) 2001, 2003]

List-IList-II
(a) Discovery of MesonHideki Yukawa
(b) Discovery of PositronC.D. Anderson and U.F. Hess
(c) Theory of energy production in the sun and starsH.A. Bethe
(d) Synthesis of transuranic elementsEnrico Fermi
Correct Answer: (d)
Solution:

In 1935 Meson particles were discovered by Japanese physicist Hideki Yukawa. Positron, the antiparticle or the antimatter counterpart of the electron was discovered by C.D. Anderson and U.F. Hess in 1932. In 1938, Hans Albrecht Bethe described the nuclear reactions that power the sun and other stars.

In synthesis of transuranic elements, Glenn T. Seaborg played an important role instead of Enrico Fermi. The fact is that he attempted to prepare a transuranic element in 1934 in Rome but failed to do so.

2. Which one of the following is not correct: [U.P.P.C.S. (Pre) 1999]

Correct Answer: (b) The breaking apart of the nucleus of an atom is called fusion.
Solution:

Option (b) is not correct. It is because the breaking apart of the nucleus of an atom is called fission not fusion. Fission is a process in which the nucleus of an atom splits into smaller parts.

3. Read the following statements- [U.P.P.C.S. (Pre) 1994]

Statement (A): Ernest Rutherford said in Royal Society that a man will never be able to get nuclear energy.

Reason (R): He was confident that the Law of Einstein will fail and the volume will not be converted to energy.

Select your answer in the code given below:

Correct Answer: (a) Both (A) and (R) are true and (A) is the correct explanation of (A).
Solution:

According to question both statement and reason are correct and reason (R) is the correct explanation of statement (A).

4. One of these particles is claimed to have invented which rebut the Einstein's theory of relativity: [U.P.P.C.S. (Pre) 2009]

Correct Answer: (a) Microwave photon
Solution:

The two physicists Gunter Nimtz and Alfons Stahlhofen of the University of Koblenz, Germany claimed that they had propelled microwave photons faster than the speed of light.

This would be the direct violation of a key content of Einstein's special theory of relativity that states that nothing under any circumstance can exceed the speed of light.

5. Cyclotrons are used to accelerate: [U.P.P.C.S. (Pre) 1997]

Correct Answer: (b) Protons
Solution:

Cyclotron is a machine used to accelerate charged particle such as alpha particles, deuteron, proton etc. up to a very high speed.

6. Which one of the following can be used to confirm whether drinking water contains a gamma emitting isotope or not? [I.A.S. (Pre) 1995]

Correct Answer: (c) Scintillation counter
Solution:

Scintillation counter is an instrument for detecting and measuring ionizing radiation by using the excitation effect of incident radiation on a scintillator material, and detecting the resultant light pulses.

7. The energy of Sun is released due to: [42ⁿᵈ B.P.S.C. (Pre) 1997, R.A.S/R.T.S. (Pre) 1993]

Correct Answer: (b) Nuclear Fusion
Solution:

The Sun produces energy by the nuclear fusion in its core. Since there is a huge amount of hydrogen in the core, these atoms stick together and fuse into a helium atom. This energy is then radiated out from the core and moves across the solar system.

This is the main source of energy for the Sun and stars. Besides that the gravitational contraction in stars is also the source of their energy.

8. Stars obtain their energy from: [U.P.P.C.S. (Pre) 2000]

1. Nuclear fusion

2. Gravitational contraction

3. Chemical reaction

4. Nuclear fission

Select your answer from the codes given below:

Code:

Correct Answer: (a) 1 and 2
Solution:

The Sun produces energy by the nuclear fusion in its core. Since there is a huge amount of hydrogen in the core, these atoms stick together and fuse into a helium atom. This energy is then radiated out from the core and moves across the solar system.

This is the main source of energy for the Sun and stars. Besides that the gravitational contraction in stars is also the source of their energy.

9. The stars receive their energy from which of the following? [Uttarakhand P.C.S. (Pre) 2006]

Correct Answer: (a) Nuclear fusion
Solution:

The Sun produces energy by the nuclear fusion in its core. Since there is a huge amount of hydrogen in the core, these atoms stick together and fuse into a helium atom. This energy is then radiated out from the core and moves across the solar system.

This is the main source of energy for the Sun and stars. Besides that the gravitational contraction in stars is also the source of their energy.

10. Which one of the following is the source of renewable energy in stars? [U.P.P.C.S. (Pre) 2009]

Correct Answer: (a) Hydrogen changes into helium.
Solution:

The Sun produces energy by the nuclear fusion in its core. Since there is a huge amount of hydrogen in the core, these atoms stick together and fuse into a helium atom. This energy is then radiated out from the core and moves across the solar system.

This is the main source of energy for the Sun and stars. Besides that the gravitational contraction in stars is also the source of their energy.