In Bohr's atomic model of hydrogen, let K, P and E are the kinetic energy, potential energy and total energy of the electron respectively. Choose the correct option when the electron undergoes transitions to a higher level :

Choose the correct option from the following options given below :

Nucleus A is having mass number 220 and its binding energy per nucleon is 5.6 MeV. It splits in two fragments 'B' and 'C' of mass numbers 105 and 115. The binding energy of nucleons in 'B' and 'C' is 6.4 MeV per nucleon. The energy Q released per fission will be :

A hydrogen atom in ground state absorbs 12.09 eV of energy. The orbital angular momentum of the electron is increased by :

The momentum of an electron revolving in $${\mathrm{n}}^{\text{th }}$$ orbit is given by : (Symbols have their usual meanings)

The magnetic moment of an electron (e) revolving in an orbit around nucleus with an orbital angular momentum is given by :

Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength $$\lambda$$. The value of principal quantum number '$$n$$' of the excited state will be : ($$\mathrm{R}:$$ Rydberg constant)

The disintegration rate of a certain radioactive sample at any instant is 4250 disintegrations per minute. 10 minutes later, the rate becomes 2250 disintegrations per minute. The approximate decay constant is : $$($$Take $${\log }_{10}1.88=0.274)$$

A nucleus of mass $$M$$ at rest splits into two parts having masses $$\frac{M^{\prime }}{3}$$ and $${{2M'} \over 3}(M'

Mass numbers of two nuclei are in the ratio of $$4:3$$. Their nuclear densities will be in the ratio of

What is the half-life period of a radioactive material if its activity drops to $$1/16^{\text{th }}$$ of its initial value in 30 years?

The activity of a radioactive material is $$6.4\times 10^{-4}$$ curie. Its half life is 5 days. The activity will become $$5\times 10^{-6}$$ curie after :

The half life period of a radioactive substance is 60 days. The time taken for $$\frac{7}{8}$$th of its original mass to disintegrate will be :

A radioactive sample decays $$\frac{7}{8}$$ times its original quantity in 15 minutes. The half-life of the sample is

Find the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its (i) second permitted energy level to the first level, and (ii) the highest permitted energy level to the first permitted level.

Read the following statements : (A) Volume of the nucleus is directly proportional to the mass number. (B) Volume of the nucleus is independent of mass number. (C) Density of the nucleus is directly proportional to the mass number. (D) Density of the nucleus is directly proportional to the cube root of the mass number. (E) Density of the nucleus is independent of the mass number. Choose the correct option from the following options.

A cylinder of fixed capacity of 44.8 litres contains helium gas at standard temperature and pressure. The amount of heat needed to raise the temperature of gas in the cylinder by 20.0$${}^{\circ }$$C will be : (Given gas constant R = 8.3 JK$$-$$1-mol$$-$$1)

In van der Waal equation \left[ {P + {a \over {{V^2}}}} \right] [V $$-$$ b] = RT; P is pressure, V is volume, R is universal gas constant and T is temperature. The ratio of constants {a \over b} is dimensionally equal to :

At what temperature a gold ring of diameter 6.230 cm be heated so that it can be fitted on a wooden bangle of diameter 6.241 cm ? Both the diameters have been measured at room temperature (27$${}^{\circ }$$C). (Given : coefficient of linear thermal expansion of gold $$\alpha$$L = 1.4 $$\times$$ 10$$-$$5 K$$-$$1)

Starting with the same initial conditions, an ideal gas expands from volume V1 to V2 in three different ways. The work done by the gas is W1 if the process is purely isothermal, W2, if the process is purely adiabatic and W3 if the process is purely isobaric. Then, choose the correct option