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1. COMSATS University Islamabad, Lahore Campus
√□ Sessional-1 SP 2020 Group A
Course Title: Electronics Course Code: Phy 234 Credit Hours: 3
Course Instructor/s: Dr. M. Yasir Rafique Program Name: BS Physics
Semester: 5th
Batch: SP-19-BPH Section: A Date: 2-04-2021
Time Allowed: 1 h Maximum Marks: 15
Student’s Name: Reg. No.
Important Instructions / Guidelines:
• Exchange of anything/use of mobile phone is prohibited
• On answer sheet don’t write statement/diagram of question. Just write question no. and part
no and solve.
Q1. [1+1+1+2=5]
Determine the voltage output waveform of each circuit
(a)
(b)
(c)

2. (d)
Q.2 [2]
The input voltage waveform to output waveform are given below. Determine and draw the
required circuit diagram (using diode, capacitor, resistor whatever is necessary).
Input Output
(a)
(b)
Q.3 [2]
Consider the meter indications in each circuit of Figure below, and determine whether the diode
is functioning properly, or whether it is open or shorted. Assume the ideal model.
(a)
(b)

3. Q4. [2]
(a) How the barrier potential across the pn junction created? Briefly explain. (1)
(b) Draw energy band diagram and I-V characteristic curve of PN junction diode (1)
Q.5 [4]
A full-wave rectifier with a capacitor-input filter provides a dc output voltage of 30 V to a 3.7
kΩ load. Determine the minimum value of filter capacitor if the maximum peak-to-peak
ripple voltage is to be 0.6 V.