RTU 2016 Question Paper Semester I Basic Electrical & Electronics Engineering

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1E2005
B. Tech I Sem. (Main/Back) Exam. Jan.2016
N 105 Basic Electrical & Electronics Engineering
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F{ Common to all Branch

Time: 3 Hours Maximum Marks: 80
Min. Passing Marks: 24
Instructions to Candidates :
Axempt any five questions, selecting one question from each unit. All questions
carry equal marks. Schematic diagrams must be shown whereyer necessary. Any
data you feel missing suitably be assumed and stated clearly.
Units of quantities used./calculated must be stated clearly.
Use of following supporting material is permitted during examination.
1. NIL 2. NIL

UNIT.I
Q.1 (a) Find the current in branch AB is the unbalanced bridge using noble analysis, as
shown in Fig 1. I (a) A t8l

40v
fig 1.1 (a)

(b) 'State and explain Theremins theorem with suitable example. t8l

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OR

Q.1 (a) Find current in 5C) resistance using superposition theorem in Fig l.l (b) t8l

sQ\/+
5V,

(b) Find the values of unknown currents I1, Iz, I-r and unknown resistances R| and R2,
as shown in Fig I .(b) t8l
r 0.2O

I l0v

fig 1(b)

UNIT-II
Q.2 (a) Define the following with suitable diagram: t61

(i) RMS values
(ii) Form factor
(iii) Peak factor
(iv) Phase angle
(b) In the act shown in fig (2). I determine the voltage at a frequency of50Hz to be
applied across AB in order that cunent in the circuit is 10A. Draw the phases
dia. t10l
10c)
5c} 0.02H

10Q

[1E20os] Page 2 of 4 [46eoo]

OR
Q.2 (a) Three sinusoidal voltages acting in series are given by:
Vr = 10 sin 440 t
Vz= 10J7sin (440t-45")
V: = 20 cos 440 t
Ilnd :
(a) The expression for resultant voltage
(b) frequency and RMS value of resultant voltage t8I
(b) How power can be measured using two wattmeter method for balance load?
Derive an expression - tan O = ..6,(*'
- *,1
(w,+wrJ t8l

UNIT.III
Q.3 (a) Derive the EMF equation for a single phase transformer and deduce the
expression for transformation ratio. t6+2=81
(b) Explain the principle of operation of 3- phase induction motor. t8l

OR
Q.3 (a) Explain in detail the Applications of DC Machines. t8l
(b) A 200 KVA, 6600/400 v, 50Hz single phase transformer has 80 turns on the
secondary and cross sectional area of the care is 80sq.cm. Neglect losses,
calculate: t8l
(i) Full load primary and secondary current
(ii) The no. of primary tums
(iii) Peak flux density
(iv) Maximum flux value in the care

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UNIT.IV
Q.4 (a) Expiain the working of a tra sistor as an ampliher. t81
(b) Explain the following gates: t8l
(D AND gate
(ii) OR gate
(iii) NOT gate
(iv) EX-OR gate
OR
Q.a (a) Write short on (any one) t8l
(i) Photovoltaic cell
(ii) Rectifiers
(b) Solve the following: - t8l
(i) (1057)ro = (X)z find X
(ii) (375)10 = (Y)s find Y
(iii) (1 101 1.1101, - (Z)rc find Z
UNIT.V
Q.s (a) Derive the mathematica'l expression of modulation index for frequency
modulated wave. Compare FM with AM [6+2=8]
(b) Write short on: - t8l
(D RTD
(ii) Strain Gauges
OR
Q.5 (a) A sinusoidal carrier wave of frequency 2 MHz and amplitude 20mv is amplitude
modulated by a sinusoidal wave of frequency 5 KHz. Determine the frequency
and amplitude of side bands. Consider modulation index as 0.8. t8l
(b) Write short note on: - (anY one) t8l
(i) Bimetallic strip
(ii) Classification of IC's
(iii) Thermo couple

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