UNIT – IV
(Electromagnetic Induction & Alternating current)
Group-A
( 1 mark each)
1) Write the S.I. unit of magnetic flux
pqEcdh; QyDl dk
S.I ek=d
fy[ksAa
2) Write the unit and dimension of co-efficient of self Induction
LoçsjdRo xq.kkad dh fcek ,oa ek=d fy[ksAa
3) What is impedance ?
çfrck|k D;k gksrh gS\
4) What is power factor?
'kfDr xq.kkad D;k gS\
5) What is the frequency of D.C.?
D.C. dh
vko`fr D;k gksrh gS\
6) What is the cause of induced e.m.f. in a closed coil ?
fdlh cUn dq.Myh esa fo|qr okgd cy ds çsj.k dk dkj.k D;k gS\
7) What is power consumed in pure capacitive A.C. circuit
çR;korhZ/kkjk ifjiFk esa 'kq) /kkfjrk jgus ij 'kfDr miHkksx fdruk gksrk gS\
8) What is the phase relation between current and voltage in the circuit containg resistance
and capacitance ?
fdlh çR;korhZ/kkjk ifjiFk esa çfrjks/k rFkk la/kkfjr ds jgus ij /kkjk ,oa eksgrst ds
chp D;k dyk lac/a k gksrk gS\
9) What is the power consumed in check coil ?
pksd dq.Myh esa fdruh 'kfDr dk {k; gksrk gS\
10) What is the R.M.S value of A.C. over a complete cycle ?
fdlh çR;koÙkhZ /kkjk dk ,d iw.kZ pØ esa ewy ek/; oxZ eku fdruk gksrk gS\
11) The R.M.S. value of alternating e.m.f. is 180 volt, what is its peak value ?
;fn çR;koÙkhZ /kkjk ds ewy ek/; oxZ dk eku 180 HkksYV gks rks bldk f'k[kj eku
D;k gksxk\
12) Which value of A.C. is measured by A.C. Ameter ?
A.C vkEehVj
ds }kjk çR;koÙkhZ /kkjk ds fdl eku dks ukik tkrk gS\
13) What is the peak value of 220 volt A.C ?
220 HkksYV
A.C. dk
f'k[kj eku D;k gS\
14) What is the reactance of a capacitor in a D.C. circuit ?
D.C ifjiFk
esa /kkfjrh; çfr?kkr fdruk gksrk gS\
15) What is the unit of reactance ?
çfr?kkr dk ek=d D;k gS\
16) What is the reactance of an Inducter in A.C. circuit ?
çR;koÙkhZ /kkjk ifjiFk esa çsjdRo dk çfr?kkr fdruk gksrk gS\
17) What is the impedance in L.C.R. series circuit at electric resonance ?
fo|qrh; vuqeku dh fLFkfr esa
L-C-R Js.kh
Øe ifjiFk dh çfrck/kk fdruh gksrh gS\
18) What is value of impedance of L-R circuit ?
L-R ifjiFk
dh çfrck/kk fdruh gS\
19) Write the value of impedance of C-R circuit ?
C-R ifjiFk
dh çfrck/kk fdruh gS\
20) Write the formula for resonance frequency ?
vuqukn vko`fr ds fy, ,d O;atd fy[ksAa
Group-B
( 2 marks each)
1) What is eddy current and by which law its direction is determined.
Hk¡oj /kkjk,¡ D;k gS rFkk budh fn'kk fdl fu;e ls çkIr gksrh gS\
2) What is the co-efficient of self Induction and write its unit.
LoçsjdRo xq.kkad D;k gS rFkk bldk ek=d crk,¡A
3) What is Mutual Induction and write its unit.
vU;ksUVj çsjdRo xq.kkad D;k gS rFkk bldk ek=d crk,¡A
4) State and explain the lenz’s law
ysUt dk fu;e fy[ksa vkSj O;k[;k djsAa
5) State Faraday’s laws of electromagnetic Induction.
QSjkMs ds fo|qr pqEcdh; çsj.k ds fu;eksa dks fy[ksAa
6) How does Lenz’s law obey the law of conservation of energy
ysUt dk fu;e fdl çdkj mtkZ laj{k.k ds fu;e ds vuqdy
w gS\
7) Define alternating current and write its equation.
çR;koÙkhZ /kkjk dks ifjHkkf"kr djsa rFkk bldk lehdj.k fy[ksAa
8) Define alternating e.m.f. and write its equation.
çR;koÙkhZ fo|qr ok/d cy dh ifjHkk"kk nsa rFkk bldk lehdj.k fy[ksAa
9) Define peak value of A.C. of Give relation between peak value and virtual value of current.
çR;koÙkhZ /kkjk ds f'k[kj eku dh ifjHkk"kk nsa rFkk /kkjk ds f'k[kj eku ,oa vkHkklh
eku ds chp lac/a k dk mYys[k djsAa
10) Define R.M.S. or virtual value of alternating current.
çR;koÙkhZ /kkjk ds ewy ek/;oxZ eku ;k vkHkklh eku dh ifjHkk"kk nsAa
11) What is wattle’s current ?
okVghu /kkjk D;k gksrh gS\
12) Write the principle of A.C. Generator.
çR;koÙkhZ /kkjk tfu= ds fl)kUr dk mYys[k djsAa
13) On which principle the working of a transformer is based ?
VªkUlQWkeZj dh fØ;k fof/k fdl fl)kUr ij vk/kkfjr gS\
14) What is chock coil and why it is used in A.C. circuit ?
pksd dq.Myh D;k gS rFkk çR;koÙkhZ /kkjk ifjiFk esa bldk D;k mi;ksx gS\
15) Write the condition for resonance in L.C.R. circuit.
fdlh
L.C.R. ifjiFk
esa vuqokn ds fy, D;k çfrcU/k gS\
Group-C
( 3 marks each)
1) Show mathematically the average value of alternating current is zero in a complete cycle.
xf.krh; fof/k ls fn[kk,¡ fd ,d iw.kZ pØ esa çR;koÙkhZ /kkjk dk vkSlr eku 'kwU; gksrk
gSA
2) Find the expression for impedance of L-R circuit.
L.R.
ifjiFk dh çfrck/kk dh x.kuk djsAa
3) Find expression for impedance of L.C.R. circuit.
L-C-R
ifjiFk dh çfrck/kk ds fy, O;atd çkIr djsAa
4) Find the co-efficient of self-induction for a solenoid.
fdlh ifjukfydk ds fy, LoçsjdRo xq.kkad dk eku Kkr djsAa
5) Discuss losses in a transformer.
fdlh VªkUlQWkeZj esa gksus okys mtkZ {k; dh ppkZ djsAa
6) Define at least two difference between A.C. and D.C.
A.C vkSj D.C esa
nks vUrj crk,¡A
7) What is power factor ? Calculate power factor for a pure inductive or capacitive A.C.
Circuit.
'kfDr xq.kkad D;k gS\ çR;koÙkh/kkjk ifjiFk esa 'kq) lapkfjr vFkok 'kq) çsjdRo jgus
ij 'kfDr xq.kkad dk eku çkIr djsAa
Group-D
( 5 marks each)
1) Discuss with neat Diagram the principle construction and working of an A.C. Generator.
,d LoPN fp= ds }kjk çR;koÙkhZ /kkjk tfur dh cukoV rFkk dk;Z fof/k dk fl)kUr
lfgr o.kZu djsAa
2) What is a transformer & Discuss its principle, construction and working with diagram.
VªkUlQWkeZj D;k gS\ ,d vkjs[k ds }kjk bldh cukoV ,oa dk;Z fof/k dk fl)kUr
lfgr o.kZu djsAa
3) What do you mean by power in A.C ? Find expression for power consumed in a general
A.C. Circuit.
çR;koÙkhZ /kkjk ifjiFk ds 'kfDr xq.kkad dk D;k rkRi;Z gS\ fdlh lkekU; çR;koÙkhZ
/kkjk ifjiFk esa mi;qDr 'kfDr ds fy, ,d O;atd çkIr djsAa
4) (a) Differentiate between, resistance, reactance and impedance.
(b) Find a formula for emf induced in coil rotating in a uniform magnetic field.
¼a½ çfrjks/k] çfr?kkr ,oa çfrck/kk esa vUrj Li"V djsAa
¼b½ le:i pqEcdh; {ks= esa ?kwf.kZr ,d dq.Myh esa çsfjr fo|qr okgd cy ds fy,
O;atd çkIr djsAa