MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Forward Bias

For a junctio...

Question

For a junction diode the ratio of forward current ( $I_{f}$ ) and reserve current ( $I_{r}$ ) is
[ $e =$ electronic charges,
$V =$ voltage applied across junction,
$K =$ Boltzmann constant,
$T =$ temperature in Kelvin]

A

e^{- V / K T}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

e^{V / K T}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

(e^{- e V / K T} + 1)

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

e^{e V / K T} - 1

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $e^{e V / K T} - 1$
Current in junction diode, $I = I_{0} (e^{e V / K T} - 1)$
In forward biasing, $V$ is positive ; In reverse bias $V$ is negative. Then $I_{r} = I_{0}$
$\frac{I_{F}}{I_{r}} = \frac{I_{0} (e^{e V / K T} - 1)}{I_{0}} = (e^{e V / K T} - 1)$

Suggest Corrections

thumbs-up

0

Similar questions

Consider a p-n junction diode having the characteristic $i = i_{0} (e^{e V / k T} - 1)$ where $i_{0} = 20 μ A .$ The diode is operated at $T = 300 K .$ (a) Find the current through the diode when a voltage of 300 mV is applied across it in forward bias. (b) At what voltage does the current double ?

Q. The current−voltage characteristic of an ideal p-n junction diode is given by

i = i_{0} (e^{e V / K T} - 1)

where, the drift current i₀ equals 10 µA. Take the temperature T to be 300 K. (a) Find the voltage V₀ for which

e^{e V / k T} = 100 .

One can neglect the term 1 for voltages greater than this value. (b) Find an expression for the dynamic resistance of the diode as a function of V for V > V₀. (c) Find the voltage for which the dynamic resistance is 0.2 Ω.

Q. In a p-n junction diode, the current I can be expressed as

I = I_{0} e x p (\frac{e V}{2 K_{B} T} - 1)

I_{0}

is called the reverse saturation current,

V

is the voltage across the diode and is positive for forward bias and negative for reverse bias, and

I

is the current through the diode,

k_{B}

is the Boltzmann constant

(8.6 \times 10^{- 5} e V / K)

T

is the absolute temperature. If for a given diode

I_{o} = 5 \times 10^{- 12}

A

T = 300 K

, then
(a) What will be the forward current at a forward voltage of

0.6 V

?(b) What will be the increase in the current if the voltage across the diode is increased to

0.7 V

?(c) What is the dynamic resistance?(d) What will be the current if reverse bias voltage changes from

1 V

2 V

If $K$ is the Boltzmann constant, the average kinetic energy of a gas molecule at absolute Temperature $T$ is

Q. One junction of a certain thermoelectric couple is at a fixed temperature

T_{r}

and the other junction is at temperature T. The thermo-electromotive force for this is expressed by

E = k (T - T_{r}) [T_{0} - \frac{1}{2} (T + T_{r})]

. At temperature

T = \frac{1}{2} T_{0}

, the thermoelectric power is :

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

PN Junction

PHYSICS

Watch in App

explore_more_icon

Explore more

Standard XII Physics

Join BYJU'S Learning Program

CrossIcon