Which of the following is true for number of spectral lines in going from Lyman series to Pfund series?
Options
(a) Increases (b) Decreases (c) Unchanged (d) May decrease or increase
Correct Answer: […]
Moderator used in nuclear reactor is
Options
(a) Ice (b) Boron rods (c) Cadmium rods (d) Heavy water
Correct Answer:
Heavy water
Explanation:
No explanation available. Be the first to write the explanation […]
An electron of a stationary hydrogen atom passes from the fifth energy level to the ground level. The velocity that the atom acquired as a result of photon emission will be: (m is the mass […]
An electron in the hydrogen atom jumps from excited state n to the ground state. The wavelength so emitted illuminates a photosensitive material having work function 2.75 eV. If the stopping potential of the photoelectron […]
An electron in hydrogen atom makes a transition n₁ → n₂ where n₁ and n₂ are principal quantum number of the two states. Assuming Bohr’s model to be valid the time period of the electron […]
An alpha nucleus of energy 1/2 mv² bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to
Options
(a) 1 / […]
A certain mass of Hydrogen is changed to Helium by the process of fusion. The mass defect in fusion reaction is 0.02866 a.m.u. The energy liberated per a.m.u. is (Given : 1 a.m.u. = 931 […]
α- particles, β – particles and γ – rays are all having same energy. Their penetrating power in a given medium in increasing order will be
Options
(a) β, γ, α (b) γ, […]
If an electron and a positron annihilate, the energy released is
Options
(a) 3.2×10⁻¹³ J (b) 1.6×10⁻¹³ J (c) 4.8×10⁻¹³ J (d) 6.4×10⁻¹³ J
Correct Answer:
1.6×10⁻¹³ J
Explanation:
No explanation available. Be […]
A nucleus at rest splits into two nuclear parts having radii in the ratio 1:2. Their velocities are in the ratio
Options
(a) (4:1) (b) (8:1) (c) (2:1) (d) (6:1)
Correct Answer:
(8:1)
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