Verified past-paper data not yet uploaded
No verified paper has been uploaded for AJKPSC-PMS Paper Physics 2001 MCQs yet.
The MCQs below are drawn from the Physics subject category.
Showing 2181–2190
of 15583 MCQs
Page 219 / 1559
2181
In the nucleus of Na-23, the numbers of protons, neutrons and electrons is
Report
Correct Option
Explanation
The nucleus of Na-23 has 11 protons and 12 neutrons and contains no electrons, so A is correct.
2182
The following equation represents induced transmutation (Be) + He -> C12 + x; in this equation x represents
Report
Correct Option
Explanation
The reaction Be + He → C + neutron is a standard induced transmutation producing a free neutron.
2183
(123) The particle which is 7000 times more massive than the electron is called:
Report
Correct Option
Explanation
An alpha (a) particle has mass ≈ 4 amu ≈ 7000 times the electron mass, matching option (a).
2184
The average binding energy per nucleon of an atomic nucleus is
Report
Correct Option
Explanation
The typical average binding energy per nucleon for stable nuclei is about 7.5 MeV, matching option A (OCR answer key).
2185
The mass of a proton is equal to
Report
Correct Option
Explanation
The proton mass is approximately 1.673 × 10^-27 kg, matching option A.
2186
Balmer identified the spectral lines in the spectrum of hydrogen in
Report
Correct Option
Explanation
Balmer's formula for hydrogen spectral lines dates to 1885, making option B correct.
2187
If the radius of the first orbit of the hydrogen atom is 5.29 × 10^-11 metre, the radius of the second orbit will be
Report
Correct Option
Explanation
Bohr radii scale as n^2, so the second orbit (n=2) has radius 4 times the first: 4 × 5.29 × 10^-11 = 2.116 × 10^-10 m (which equals 21.16 × 10^-11 m).
2188
After emission of an α-particle, mass number and charge number of the resulting nucleus will be
Report
Correct Option
Explanation
Emission of an alpha particle reduces mass number by 4 and atomic number by 2, so A→A-4 and Z→Z-2.
2189
When Li is bombarded with a proton what is formed?
Report
Correct Option
Explanation
The reaction Li + p can produce two alpha particles (2 He nuclei) in known nuclear transmutations.
2190
The half-life of a radioactive substance is 6 years. What is the time taken by 12 g of this substance to decay completely?
Report
Correct Option
Explanation
Radioactive decay is asymptotic; theoretically it never reaches zero, so decay 'completely' would take an infinite time.
