51.

Calculate the kinetic energy of the electron having wavelength 1 nm

• 2.1 eV

• 3.1 eV

• 1.5 eV

• 4.2 eV

A light ray is incident on a glass slab, it is partially reflected and partially transmitted. Then the reflected ray is

• completely polarised and highly intense.

• partially polarised and poorly intense.

• partially polarised and highly intense.

• completely polarised and poorly intense.

For a common-emitter transistor, input current is 5A, ( β = 100 circuit is operated at load resistance of 10 kΩ, then voltage across collector emitter will be

• 5 V

• 10 V

• 12.5 V

• 7.5 V

The nucleus  ${}_{\mathrm{n}}{}^{\mathrm{m}}\mathrm{X}$ emits one $\mathrm{\alpha }$  particle and 2β- particles. The resulting nucleus is

• ${}_{\mathrm{n}-2}{}^{\mathrm{m}-4}\mathrm{Y}$

• ${}_{\mathrm{n}-4}{}^{\mathrm{m}-6}\mathrm{Z}$

• ${}_{\mathrm{n}}{}^{\mathrm{m}-6}\mathrm{Z}$

• ${}_{\mathrm{n}}{}^{\mathrm{m}-4}\mathrm{X}$

Assertion:  A thick lens shows more chromatic aberration.

Reason:  Thick lens behave as many thin lenses.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion:  Bohr's atomic model cannot be used to explain multiple electron species.

Reason: It does not take inter-electronic interactions in account.

• If both assertion and reason are true and reason
  is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion: The focal length of objective lens in telescope is much more than that of eye piece.

Reason: Telescope has high resolving power due to large focal length.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion: Total energy of electron in an hydrogen atom is negative.

Reason: It is bounded to the nucleus.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion:  More energy is released in fusion than fission. 

Reason:  More number of nucleons take part in fission.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Asserion: γ-radiation emission occurs after $\mathrm{\alpha } \mathrm{and} \mathrm{\beta }$ decay.

Reason: Energy levels occurs in nucleus.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.