A transistor connected at common emitter mode contains load resistance of 5 kΩ and an input resistance of 1 kΩ. If the input peak voltage is 5 mV and the current gain is 50, find the voltage gain.

• 250

• 500

• 125

• 50

The two coherent sources with intensity ratio β produce interference. The fringe visibility will be

• $\frac{2 \sqrt{\mathrm{\beta }}}{1 + \mathrm{\beta }}$

• 2 β

• $\frac{2}{\left(1 + \mathrm{\beta }\right)}$

• $\frac{\sqrt{\mathrm{\beta }}}{1 + \mathrm{\beta }}$

For a situation shown in figure, find the refrective index of glass so that it will suffer total internal reflection at the vertical surface

• 1.732

• 1.5

• 1.31

• 1.6

The output for the given, circuit is

• $\left( \mathrm{A} + \mathrm{B} \right)$$·$ $\overline{\mathrm{B}}$

• (A $·$ B) $·$ B

• ( A + B )$·$B

• ( A $·$ B ) + B

Assertion: In YDSE bright and dark fringe are equally spaced.

Reason: It only depends upon 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: Generally heavy nuclei are unstable.

Reason: It has more neutrons and protons.

• 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:  Electron microscope has more resolving power than optical microscope.

Reason:  We can control the energy of electron.

• 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.

58.

Assertion: When a certain wavelength of light fall on a metal surface it ejects electron. 

Reason: Light has wave nature.

• 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:  Electrons in the atom are held due to Coulomb forces. 

Reason:  The atom is stable only because the centripetal force due to Coulomb's law is balanced by the centrifugal force.

• 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:  When an object is placed between two plane parallel mirrors, then all the images found are of equal intensity. 

Reason : In case of plane parallel mirrors, only two images are possible.

• 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.