An electron in hydrogen atom makes a transition n₁ → n₂
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 […]
Physics
An alpha nucleus of energy 1/2 mv² bombards a heavy nuclear target of charge Ze
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
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.
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
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
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 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
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
In the series resonance the value of impedence is 3 Ω and the resistance is 4Ω,
In the series resonance the value of impedence is 3 Ω and the resistance is 4Ω, then the value of power factor of the circuit is
Options
(a) (4/3) (b) (3/4) (c) zero […]
An electric bulb has a rated power of 50W at 100 V. if it used on an a.c. source
An electric bulb has a rated power of 50W at 100 V. if it used on an a.c. source 200V, 50 Hz, a choke has to be used in series with it. This choke should […]