 MORE IN Elements of Electrical Engineering
GTU First Year Engineering (Semester 1)
Elements of Electrical Engineering
December 2015
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Objective Question ? select only one option out of four (MCQ)
1(a)1 Which of the following material has nearly zero temperature co-efficient of Resistance -
[a] Carbon
[b] copper
[c] Porcelain
[d] Manganin
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1(a)2 The unit of absolute permittivity of a medium is
[b] newton-m
[d] joule/coulomb
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1(a)3 The unit of resistivity is
[a] Ohm / m
[b] Ohm-m
[c] mho/m [d] mho-m
1 M
1(a)4 Time constant of an R-C ckt. may be defined as
[a] time during which capacitor voltage rises to 0.632 of its initial value
[b] time during which charging current falls to 0.37 of its initial max. Value
[c] time during which capacitor voltage falls to 0.632 of its final steady value
[d] time during which charging current rises to 0.37 of its initial max. value
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1(a)5 The unit of reluctance is
[a] AT / Wb
[b] Wb / AT
[c] 1/Henry
[d] either [b] or [c]
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1(a)6 Wh efficiency of lead-acid cell is ______ Ah efficiency.
[a] greater than
[b] smaller than
[c] equal to
[d] none of this
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1(a)7 The value of form factor is
[a] 11.1
[b] 1.11
[c] 1.414
[d] 14.14
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1(b)1 The value of power factor is zero for
[a] purely inductive ckt.
[b] purely resistive ckt.
[c] purely capacitive ckt.
[d] either [a] or [c]
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1(b)2 For a series resonance condition of AC circuit impedance is
[a] minimum
[b] maximum
[c] zero
[d] infinity
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1(b)3 The filament used in incandescent lamp is made of
[a] copper
[b] aluminium
[c] nichrome
[d] tungsten
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1(b)4 The value of crest factor is
[a] 11.1
[b] 1.11
[c] 1.414
[d] 14.14
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1(b)5 For a parallel resonance condition of a AC circuit current is
[a] minimum
[b] maximum
[c] zero
[d] infinity
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1(b)6 For unity power factor load of 3-phase ckt.,if we measure the power by 2- wattmeter method then readings of wattmeters are
[a] one wattmeter shows zero reading
[b] equal & +ve sign
[c] equal & opposite sign
[d] both shows zero reading The power factor of R-C series Ac ckt. is
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1(b)7 The power factor of R-C series Ac ckt. Is
[a] unity
[b] lagging