# ONLINE MCQ EE-ELECTROMAGNETIC INDUCTION 2

Q11. Mutually inductance between two
magnetically-coupled coils depends on
A.  permeability of the core
B.  the number of their turns
C.  cross-sectional area of their common
core
D.  all of the above
 \$(document).ready(function(){ \$(‘#loaddata2110’).click(function(){ qid2110=\$(‘#qid2110’).val(); section2110=\$(‘#section2110’).val(); type2110=\$(‘#type2110’).val(); subtype2110=\$(‘#subtype2110’).val(); \$.post(‘../../fav’,{ qid:qid2110, section: section2110, type: type2110, subtype: subtype2110 },function(ajaxresult){ \$(‘#getrequest2110’).html(ajaxresult); qid2110=\$(‘#qid2110’).val(”); section2110=\$(‘#section2110’).val(”); type2110=\$(‘#type2110’).val(”); subtype2110=\$(‘#subtype2110’).val(”); }); }); }); Explanation:- Answer : D

Q12. An e.m.f. of 16 volts is induced in a coil
of inductance 4 H. The rate of change of
current must be
A.  64 A/s
B.  32 A/s
C.  16 A/s
D.  4 A/s
 \$(document).ready(function(){ \$(‘#loaddata2111’).click(function(){ qid2111=\$(‘#qid2111’).val(); section2111=\$(‘#section2111’).val(); type2111=\$(‘#type2111’).val(); subtype2111=\$(‘#subtype2111’).val(); \$.post(‘../../fav’,{ qid:qid2111, section: section2111, type: type2111, subtype: subtype2111 },function(ajaxresult){ \$(‘#getrequest2111’).html(ajaxresult); qid2111=\$(‘#qid2111’).val(”); section2111=\$(‘#section2111’).val(”); type2111=\$(‘#type2111’).val(”); subtype2111=\$(‘#subtype2111’).val(”); }); }); }); Explanation:- Answer : D

Q13. The co-efficient of coupling between
two air core coils depends on
A.  self-inductance of two coils only
B.  mutual inductance between two
coils only
C.  mutual inductance and self inductance
of two coils
D.  none of the above
 \$(document).ready(function(){ \$(‘#loaddata2112’).click(function(){ qid2112=\$(‘#qid2112’).val(); section2112=\$(‘#section2112’).val(); type2112=\$(‘#type2112’).val(); subtype2112=\$(‘#subtype2112’).val(); \$.post(‘../../fav’,{ qid:qid2112, section: section2112, type: type2112, subtype: subtype2112 },function(ajaxresult){ \$(‘#getrequest2112’).html(ajaxresult); qid2112=\$(‘#qid2112’).val(”); section2112=\$(‘#section2112’).val(”); type2112=\$(‘#type2112’).val(”); subtype2112=\$(‘#subtype2112’).val(”); }); }); }); Explanation:- Answer : C

Q14. A crack in the magnetic path of an
inductor will result in
A.  unchanged inductance
B.  increased inductance
C.  zero inductance
D.  reduced inductance
 \$(document).ready(function(){ \$(‘#loaddata2113’).click(function(){ qid2113=\$(‘#qid2113’).val(); section2113=\$(‘#section2113’).val(); type2113=\$(‘#type2113’).val(); subtype2113=\$(‘#subtype2113’).val(); \$.post(‘../../fav’,{ qid:qid2113, section: section2113, type: type2113, subtype: subtype2113 },function(ajaxresult){ \$(‘#getrequest2113’).html(ajaxresult); qid2113=\$(‘#qid2113’).val(”); section2113=\$(‘#section2113’).val(”); type2113=\$(‘#type2113’).val(”); subtype2113=\$(‘#subtype2113’).val(”); }); }); }); Explanation:- Answer : D

Q15. Higher the self-inductance of a coil,
A.  lesser its weher-turns
B.  lower the e.m.f. induced
C.  greater the flux produced by it
D.  longer the delay in establishing
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Q16. A laminated iron core has reduced
eddy-current losses because
A.  more wire can he used with less
D.C. resistance in coil
B.  the laminations are insulated from
each other
C.  the magnetic flux is concentrated in
the air gap of the core
D.  the laminations are stacked vertically
 \$(document).ready(function(){ \$(‘#loaddata2115’).click(function(){ qid2115=\$(‘#qid2115’).val(); section2115=\$(‘#section2115’).val(); type2115=\$(‘#type2115’).val(); subtype2115=\$(‘#subtype2115’).val(); \$.post(‘../../fav’,{ qid:qid2115, section: section2115, type: type2115, subtype: subtype2115 },function(ajaxresult){ \$(‘#getrequest2115’).html(ajaxresult); qid2115=\$(‘#qid2115’).val(”); section2115=\$(‘#section2115’).val(”); type2115=\$(‘#type2115’).val(”); subtype2115=\$(‘#subtype2115’).val(”); }); }); }); Explanation:- Answer : B

Q17. The core of a coil has a length of 200
mm. The inductance of coil is 6 mH. If
the core length is doubled, all other
quantities, remaining the same, the inductance
will be
A.  3 mH
B.  12 mH
C.  24 mH
D.  48 mH
 \$(document).ready(function(){ \$(‘#loaddata2116’).click(function(){ qid2116=\$(‘#qid2116’).val(); section2116=\$(‘#section2116’).val(); type2116=\$(‘#type2116’).val(); subtype2116=\$(‘#subtype2116’).val(); \$.post(‘../../fav’,{ qid:qid2116, section: section2116, type: type2116, subtype: subtype2116 },function(ajaxresult){ \$(‘#getrequest2116’).html(ajaxresult); qid2116=\$(‘#qid2116’).val(”); section2116=\$(‘#section2116’).val(”); type2116=\$(‘#type2116’).val(”); subtype2116=\$(‘#subtype2116’).val(”); }); }); }); Explanation:- Answer : A

Q18. An average Voltage of 10 V is induced
in a 250 turns solenoid as a result of a
change in flux which occurs in 0.5
second. The total flux change is
A.  20 Wb
B.  2 Wb
C.  0.2 Wb
D.  0.02 Wb
 \$(document).ready(function(){ \$(‘#loaddata2117’).click(function(){ qid2117=\$(‘#qid2117’).val(); section2117=\$(‘#section2117’).val(); type2117=\$(‘#type2117’).val(); subtype2117=\$(‘#subtype2117’).val(); \$.post(‘../../fav’,{ qid:qid2117, section: section2117, type: type2117, subtype: subtype2117 },function(ajaxresult){ \$(‘#getrequest2117’).html(ajaxresult); qid2117=\$(‘#qid2117’).val(”); section2117=\$(‘#section2117’).val(”); type2117=\$(‘#type2117’).val(”); subtype2117=\$(‘#subtype2117’).val(”); }); }); }); Explanation:- Answer : D

Q19. In an iron cored coil the iron core is
removed so that the coil becomes an air
cored coil. The inductance of the coil
will
A.  increase
B.  decrease
C.  remain the same
D.  initially increase and then decrease
 \$(document).ready(function(){ \$(‘#loaddata2118’).click(function(){ qid2118=\$(‘#qid2118’).val(); section2118=\$(‘#section2118’).val(); type2118=\$(‘#type2118’).val(); subtype2118=\$(‘#subtype2118’).val(); \$.post(‘../../fav’,{ qid:qid2118, section: section2118, type: type2118, subtype: subtype2118 },function(ajaxresult){ \$(‘#getrequest2118’).html(ajaxresult); qid2118=\$(‘#qid2118’).val(”); section2118=\$(‘#section2118’).val(”); type2118=\$(‘#type2118’).val(”); subtype2118=\$(‘#subtype2118’).val(”); }); }); }); Explanation:- Answer : B

Q20. The co-efficient of self-inductance for a
coil is given as
A.  NI/Φ