The following data was obtained for a given transistor: V C E → 10.0 V 10.0 V V B E → 0.82 V 0.72 V I B → 80 μ A 30 μ A For this data, calculate the input resistance of the given transistor.

Given, V C E → 10.0 V 10.0 V V B E → 0.82 V 0.72 V I B → 80 μ A 30 μ A We know that input resistance is the ratio of change in input voltage to the change in the input current. The change in base-emitter voltage △ V B E = 0.82 - 0.72 = 0.10 V The change in base current, Δ I B = ( 80 - 30 ) μ A = 50 × 1 0 - 6 A Hence the input resistance, r = Δ V B E Δ I B V C E = constant = 0.10 V 50 × 1 0 - 6 A = 2 000 Ω

MEDIUM

12th CBSE

IMPORTANT

Earn 100

A crystal diode having internal resistance $200 Ω$ is used as a half rectifier. If the applied voltage is $V = 50$ $s i n ω t$ volt and load resistance is $800 Ω$ , find (i) maximum output current (ii) d. c. output current (iii) d. c. output power and (iv) d. c. output voltage.

Important Questions on Semiconductor Devices and Digital Circuits

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 13

In a photodiode, the conductivity increases when the material is exposed to light. It is found that conductivity changes only if the wavelength is less than

600 n m .

What is the band gap?

h = 6 .6 \times 10^{- 34} Js, c = 3 \times 10^{8} m / s

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 1

The following data was obtained for a given transistor:

$V_{C E} \to$	$10.0 V$	$10.0 V$
$V_{B E} \to$	$0.82 V$	$0.72 V$
$I_{B} \to$	$80 μ A$	$30 μ A$

For this data, calculate the input resistance of the given transistor.

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 2

If a change of

100 μ A

in the base current of an

n-p-n

transistor causes a change of

10 m A

in its collector current, what is its

a . c

. current gain?

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 3

The ac current gain of a transistor is

120 .

What is the change in the collector current in the transistor whose base current changes by

100 μ A

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 4

A transistor has a current gain of

30 .

If the collector resistance is

6 k Ω

, input resistance is

1 k Ω

, calculate its voltage gain.

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 5

In a transistor connected in common emitter mode,

R_{C} = 4 k Ω, R_{i} = 1 k Ω,

I_{C} = 1 m A

and

I_{B} = 20 μ A

. Find the voltage gain.

R_{C}, R_{i}, I_{C}

and

I_{B}

are collector resistance, input resistance, collector current and base current respectively.

MEDIUM

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 6

In a transistor amplifier,

β = 62, R_{L} = 5000 Ω

and internal resistance of the transistor

= 500 Ω .

Calculate the voltage amplification and power amplification.

EASY

12th CBSE

IMPORTANT

PHYSICS A Reference Book for Class 12 Volume 2>Chapter 6 - Semiconductor Devices and Digital Circuits>Problems For Practice>Q 7

A transistor has

α = 0.95

. If the emitter current is

10 m A

, what is (a) the collector current, (b) the base current, and (c) gain

β

A crystal diode having internal resistance 200 Ω is used as a half rectifier. If the applied voltage is V=50sinωt volt and load resistance is 800 Ω, find (i) maximum output current (ii) d. c. output current (iii) d. c. output power and (iv) d. c. output voltage.

Important Questions on Semiconductor Devices and Digital Circuits

Learn and Prepare for any exam you want !

A crystal diode having internal resistance $200 Ω$ is used as a half rectifier. If the applied voltage is $V = 50$ $s i n ω t$ volt and load resistance is $800 Ω$ , find (i) maximum output current (ii) d. c. output current (iii) d. c. output power and (iv) d. c. output voltage.