Applied physics AD/BS University Of Sargodha (UOS) 2015

BS(CS)

Subject: BS(CS)

university of Sargodha

Ist Term final Exam 2015

Course:Busic Electronics (PHY-2210)

Time Allowed: 2:30 Hours

Maximum Marks: 80

Note: Objective part is compulsory. Attempt any four questions from subjective parts.

Objective Part

Q. 1 Write short answers of the following questions in 2-3 lines only

(16 x 2 =

32)

What is zero reference level? why we need it during voltage measurements at different

Points in electric circuit

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Differentiate transition capacitance and diffision capacitance?

Why PIN Photodiodes have Inster response than even the P-N Photodiode?

Why we need filters in the clegtronics circuits?

Which factors control the Capacitance of the capacitor?

The colour of light emitted by LED depends on what?

What is effect of temperature on barrier voltage?

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Why clectrons have greater mobility than holes in a semiconductor material

Ip Explan effect of doping on semiconductor

Distinguish between drift speed and Fermi speed?

, In an optical fibre why refractive index of core is kept higher than cladding?

Draw symbols of an air-core and ad iron-core inductor?

15) Under what condition a transistor can opcrate in active region.

Define Solar cell? Draw its symbol.

What are carrier waves?

What is Amplitude modulation?

Subjective Part (4x12 =

48)

X Dete inducer Explain eul indicue in derain,

(8)

Calculate the inductive reactance offered by a coil of inductance 250g!l to radio

frequency currents of frequencies

(i) 1MHz

(ii) 10MHz

(4)

/ Q.3 Define series cirçuit? Explain characteristics of a series resistive circuit?

(6)

A 12V battery of negligible internal resistance is connected across a paralle! combination

of 4K, 6K, and 12K resistors. Compute

(i) Combined circuit resistance

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(iii). Power supplied by the battery

(ii) Current supplied by the battery

(6)

4(a) What is Transformer? Explain principle, construction, working of Transformer

À power transfurner has 100 primary runs and 600 secondary turns (Cobbly veltage

is 120V and full load primary current is 12A, Find secondary

(i) Voltage V2

(ii) current l2

What is P-N Junction? Explain Forward and Reverse Voltage Corrent Characteristics of a

P-N junction

(4)

(12)

6(a) Explain Transistor biasing for the proper working of a PNP and NPN transistor

of Following readings are obtained in transistor cue

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1. - ImA. a - 095

(6)