Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

EASY

Earn 100

What is LED? Draw the V-I characteristics of an LED?

Important Questions on Semiconductor Devices

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Why cannot we use

Si

and

Ge

in fabrication of visible LEDs ?

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

The band gap of the semiconductor

{GaAs}_{0.6} P_{0.4}

is

1.9 eV

. If this material is used to make a Light Emitting Diode

(LED)

, the colour of the emerging light will appear

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Write the name of any one dopped semiconductor used for making light emitting diode (LED).

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

A light emitting diode is

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

What is LED? Mention two of its applications.

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

LED is constructed from

G a - A s - P

semiconducting material. The energy gap of this LED is

1.9 eV

. Calculate the wavelength of light emitted and its colour.

h = 6.63 \times 10^{- 34} J - s

and

c = 3 \times 10^{8} m s^{- 1}

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Identify the incorrect statement:

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

What is the advantage of an LED bulb over filament bulb?

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

The

I - V

characteristics of an

LED

is:

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Mention some advantages of LEDs over an incandescent lamp.

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

The

I - V

characteristic of an LED is

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Why do we use light emitting diode (LEDs) in smartphones?

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Mention various uses of LEDs.

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

The light emitted in an LED is due to:

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

What is Light emitting diode?

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Statement-1 : Light emiting diode (LED) emits spontaneous radiation.

Statement-2 : LED is forward-biased p-n junction.

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Describe the working of Light Emitting diodes (LEDs).

HARD

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Statement-1 : Light emiting diode (LED) emit spontaneous radiation.

Statement-2 : LED are forward-biased p-n junction.

EASY

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

The

I - V

characteristic of an LED is

MEDIUM

Physics>Modern Physics>Semiconductor Devices>Light Emitting Diode (LED)

Avani’s family uses filament bulbs at home while Om’s family uses LED bulbs. Which family will save more electricity? Write five other ways to save electricity.