If the radius of the first Bohr orbit of the hydrogen atom is 5.29 x 10' m, the radius of the second orbit will be

• 21.16 x 10⁻¹¹ m

• 15.87 x 10⁻¹¹  m

• 10.58 x 10⁻¹¹ m

• 2.64 x 10⁻¹¹  m

If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy required to remove the electron from the first excited state of Li²⁺ is

• 30.6 eV

• 13.6 eV

• 3.4 eV

• 122.4 eV

Which of the following is more close to a black body?

• Black board paint

• Green leaves

• Black holes

• Red roses

Wavelength of the particle whose momentum is p

• $\frac{\mathrm{h}}{\mathrm{p}}$

• hp

• $\frac{\mathrm{p}}{\mathrm{h}}$

• p + h

In nth orbit of hydrogen atom energy $\mathrm{E} = \frac{- 13.6}{{\mathrm{n}}^2} \mathrm{eV}$, then energy required to displace  electrons from n = 1 to n = 2 is

• - 10.2 eV

• 3.4 eV

• - 13.6 eV

• 1.51 eV

The minimum energy to ionize an atom is the energy required to

• add one electron to the atom

• excite the atom from its ground state to its excited state

• remove one outer most electron from the atom

• remove one inner most electron from the atom

In hydrogen atom, the electron in a given orbit has total energy -1.5 eV. The potential energy is

• 1.5 eV

• - 1.5 eV

• 3.0 eV

• - 3.0 eV

The wavelength of first Lyman series in the transition from n = 2 to n = 1 is

• 110 nm

• 120 nm

• 122 nm

• 125 nm

169.

λ₁, λ₂, λ₃ are de-Broglie wavelengths of electron, proton and $\mathrm{\alpha }$ - particle. If they are accelerated by same potential, then

• λ₁ < λ₂ < λ₃

• λ₁ >λ₂ > λ₃

• λ₁ < λ₂ > λ₃

• λ₁ > λ₂ < λ₃

Which energy state of triply ionized beryllium Be³⁺ has the same orbital radius as that of ground state of hydrogen atom ?

• n = 8 state

• n = 5 state

• n = 4 state

• n = 2 state