The control rods used in a nuclear reactor can be made up of
Options
(a) graphite (b) cadmium (c) uranium (d) barium
Correct Answer:
cadmium
Explanation:
No explanation available. Be the first to […]
In Moseley’s law √ν=a(z-b), the values of the screening constant for K-series and L-series of X-rays are respectively
Options
(a) 1,6.4 (b) 1,4 (c) 4,6 (d) 2,4
Correct Answer:
1,6.4
Explanation:
No explanation […]
The wavelength of light emitted from second orbit to first orbit in a hydrogen atom is
Options
(a) 1.215×10⁻⁷ m (b) 1.215×10⁻⁵ m (c) 1.215×10⁻⁴ m (d) 1.215×10⁻³ m
Correct Answer:
1.215×10⁻⁷ m
Explanation: […]
The sodium nucleus ₁₁Na²³ contains
Options
(a) 11 electrons (b) 12 protons (c) 23 protons (d) 12 neutrons
Correct Answer:
12 neutrons
Explanation:
No explanation available. Be the first to write the explanation […]
The Rutherford scattering experiment proves that an atom consists of
Options
(a) a sphere of positive charge in which electrons are embedded like seeds of water-melon (b) a sphere of negative charge in […]
If, an electron in hydrogen atom jumps from an orbit of level n=3 to an orbit of level n=2, emitted radiation has a frequency (R=Rydberg’s constant, c=velocity of light)
Options
(a) 3Rϲ/27 (b) […]
For principal quantum number n=3, the possible values of orbital quantum number l are
Options
(a) 1,2,3 (b) 0,1,2,3 (c) 0,1,2 (d) (-1,0,+1)
Correct Answer:
0,1,2
Explanation:
No explanation available. Be the first […]
The ionisation energy of hydrogen is 13.6 eV. The energy of the photon released when an electron jumps from the first excited state (n=2) to the ground state of hydrogen atom is
Options
The first line in Lyman series has wavelength λ. The wavelength of the first line in Balmer series is
Options
(a) 2/9 λ (b) 9/2 λ (c) 5/27 λ (d) 27/5 λ
Correct […]
The excitation potential of hydrogen atom in the first excited state is
Options
(a) 13.6 V (b) (-13.6 V) (c) 10.2 V (d) (-10 V)
Correct Answer:
10.2 V
Explanation:
Energy of […]
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