PYQ – FUNDAMENTAL OF ELE. & ELO. ENGG. (2420103) | SEMESTER 1ST AND 2ND (1ST YEAR) | Year 2023

Fundamental of Electrical and Electronics Engineering 2023 PYQ.

(Sem – I & II) Diploma Exam 2023 (Even)

(C.S.E) (Theory)

[Time: 3 Hours]             Fundamental of Electrical & Electronics (2420103)        [Full. Marks:70]

-   All questions are compulsory.

-   Marks are mentioned on the right side of each question.

 

Group A

 

Choose the most suitable answer from the following options: -   (1*20=20)

(i) For a voltage source

(a) terminal voltage is equal to the source emf

(b) terminal voltage cannot exceed source emf

(c)  terminal voltage is always lower than source emf

(d) terminal voltage is higher than the source emf

(ii) A dependent source

(a) may be a current source or a voltage source

(b) is always a voltage source

(c) is always a current source

(d) neither a current source nor a voltage source

(iii) In an ideal op-amp, the voltage gain for the common mode signal is

(a) 0

(b) 0.5

(c) 2.0

(d)  ∞

(iv) An identical op-amp, is supposed to have

(a) infinite input impedance       

(b) zero output impedance

(c) infinite band width

(d) all of the above

(v) An op-amp can amplify

(a) a. c. signal only 

(b) d. c. signal only

(c) both a. c. and d. c. signals

(d) neither d. c. nor a. c. signals

(vi) In Boolean algebra, the OR operation is performed by which properties?

(a) Associative properties

(b) Commutative properties

(c) Distributive properties

(d) all of the above

(vii) Which of the following Boolean expressions is ‘NOT TRUE’?

(a) A + 1 = A

(b) A + A’ = 1

(c) A . A = A

(d) A . A’ = 0

(viii) A NAND gate has _______ inputs and ________ outputs.

(a) high input and high output

(b) high input and low output

(c) low input and low output

(d) low input and high output

(ix) A logic gate is an electronic circuit which

(a) operates on binary algebra

(b) performs arithmetic and logic functions

(c) allows flow of electrons only in one direction

(d) alternates between 0 and 1 values

 
(x) In a magnetic material, hysteresis loss takes place primarily due to

(a) Rapid reversals of its magnetization

(b) Its high retentivity

(c) molecular friction

(d) flux density lagging behind magnetizing force

 
(xi) Conductivity is analogous to

(a) retentivity

(b) resistivity

(c) permeability

(d) inductance

(xii) For a coil having a magnetic circuit of constant reluctance, the flux is _______ to the current.

(a) directly proportional

(b) inversely proportional

(c) not related

(d) very large compared

(xiii) Which law is used in finding the direction of current in an a. c. generator?

(a) Maxwell’s law

(b) Lenz’s law

(c) Cork screw law

(d) Ampere circuital law

(xiv) Which part of the magnetic part requires largest MMF?

(a) core

(b) air gap

(c) coil

(d) inductance

 
(xv) In a series R-L-C circuit, the maximum voltage across the capacitor occurs at a frequency.

(a) double the resonant frequency  

(b) equal to resonant frequency

(c) √2  times the resonant frequency

(d) below the resonant frequency

(xvi) The ratio of active power to apparent power is known as

(a) demand factor  

(b) load factor

(c) power factor

(d) form factor

(xvii) The rms value and mean value is the same in the case of

(a) Triangular wave  

(b) sine wave

(c) square wave

(d) half wave rectified sine wave

(xviii) The purpose of the transformer core is to provide _________

(a) low reluctance path  

(b) high inductance path

(c) high capacitive path  

(d) high reluctance path

(xix) An ideal transformer will have maximum efficiency at a load such that

(a) copper loss < iron loss

(b) copper loss > iron loss

(c) copper loss = iron loss

(d) none of these

(xx) The speed of a D. C. shunt motor is required to be more than full load speed. This is possible by

(a) reducing the field current  

(b) decreasing the armature current

(c) increasing the armature current  

(d) increasing the excitation current

 

Group:-"B"

➥ Answer all Five Questions: -                         (5*4=20) 

 

2. Define passive component what are the characteristics of passive components? 

OR

 Define ideal and non-ideal voltage and current source. What are the characteristics of ideal source?

 

3. What is the symbol of operational amplifier? What is an adder amplifier? 

OR

What is the difference between inverting and non-inverting input? Why positive feedback is not used in op-amp.? Explain it,

 

4. What are the basic logic elements? Define positive logic and negative logic.  

OR

What are magnetic field lines? Justify the statement that two magnetic field lines never intersect each other.

 

5. Derive the expression for dynamically induced emf. On what factors does this emf depend? 

OR

Distinguish between resistance, impedance and reactance of an a. c. circuit.

 

6. Why dose a transformer has iron core? Explain.  

OR

What are electric motors? What are the significant parts of D. C. motor?

 

Group:- "C"

➥ Answer all Five Questions: -                         (5*6=30) 

 

7. Why silicon type transistors are more often used than germanium type? What is the significance of arrow head in the transistor symbol? Explain it.

OR

 Define and explain self and mutually induced emf. Write down difference between statically and dynamically induced emf.

 

8. State and explain the condition of resonance in a series R-L-C circuit of an ac circuit. Draw the phasor diagram also. 

OR

 Prove that the active power consumed in any Purdy capacitive circuit is zero.

 

9. Explain the principle of operation of transformer. Derive an emf equation of a transformer.  

OR

 What is a comparator? What are the applications of comparators?

 

10. Write the truth table of fundamental gates. Reason out why the NAND and NOR are called universal gates?  

OR

 Explain the following term for ac wave

RAM value

phase angle

form factor

 

11. Why is commutator needed in a de motor? Explain why the emf generated in the armature of a dc motor is called the back emf?

OR

  Why transformer are rated in KVA instead of KW? Explain Auto – transformer with suitable diagram.

 

 

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