51.

Assertion:  A diode lasers are used as optical sources in optical communication.

Reason: Diode lasers consume less energy.

• 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: Diamond glitters brilliantly. 

Reason: Diamond does not absorb sunlight.

• 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 energy (E) and momentum (p) of a phoon are related by p = E/c.

Reason: the photon behaves like a particle.

• 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 clouds in sky generally appear to be whitish. 

Reason:  Diffraction due to clouds is efficient in equal measure at all wavelengths.

• 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: Television signals are received through sky-wave propagation.

Reason: The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency

• 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 logic gate NOT can be built using diode.

Reason: The output voltage and the input voltage of the diode have 180^o phase difference.

• 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 resolving power of a telescope is more if the diameter of the objective lens is more.

Reason:  Objective lens of large diameter collects more
light.

• 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:  It is not possible to use  ³⁵Cl  as  the fuel for fusion energy.

Reason: The binding energy of  ³⁵Cl is too small.

• 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 number of electrons in a p-type silicon  semiconductor is less than the number of electrons in a pure silicon semiconductor at room temperature.

Reason: It is due to law of mass action.

• 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: In a common emitter transistor amplifier the input current is much less than the output current. 

Reason: The common emitter transistor amplifier has very high input impedance.

• 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.