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, […]
An alternating voltage e=200s in100t is applied to a series combination of R= 30Ω and an inductor of 400 mH. The power factor of the circuit is
Options
(a) 0.01 (b) 0.05 (c) […]
An ideal coil of 10 H is connected in series with a resistance of 5Ω and a battery fo 5 V. 2 second after the connection is made, the current flowing in ampere in the […]
In an AC circuit the potential differences across an inductance and resistance joined in series are respectively 16 V and 20 V. The total potential difference of the source is
Options
(a) 20.0 […]
An electric lamp is connected to 220 V, 50 Hz supply. Then the peak voltge is
Options
(a) 210 V (b) 211 V (c) 311 V (d) 320 V
Correct Answer:
311 V
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