16. Avalanche break down in a semi conductor diode occures — when?
' (A)(orwar(lbiafiexceedsacerl.ainvalue
(B) the potential value is reduced to zero
)©0 forward current exceeds a certain value
(D) areverse bias exceads a certain value
17, At which length do you have to change the brushes of a DC machine?
1 ⇀⋅ 2 ..
(&) 7 of original length (7) of original length
೫1. ↽⋅ 3 =
(ಲ) 5 of original length o) ध of original length
18, The primary and secondary connection of a distribution transformer is :

(7)
)

(A) primary and secondary star primary and secondary delta

| )© primary delta, secondary star primary star secondary delta

19. Electric field intensity is :
(A
(C) wvector quantity

(0)
(7)

scalar quantity phasor quantity

none of the above

20. The speed of ೩ 50 Hrtz Three Phase Induction Motor at full load condition is 720 RPM, the
number of poles of the motoris 2

(५) 12 (2) 8
(0) 6 o 4
21, Water heater has minimum insulation resistance of :
(ಗಿ) 1 megaohm (B) 2 megachm
(C) 0.5 megaochm (D) 0.25 mega ohm

22. The function of controll grid in a pentode tube is :

(4) to accilarate the electrons emitted from eathode
(1) to controll the sccondary emission from the plate
to collect electrons from the space charge
ம) to cantroll the number of electrons moving from cathode to plate
23, A 40 w lamp is connected across a 240 volt supply what is the resistance of the supply?
(A) 14400 Q (B) 14400
© 140 ™ 144६2
A 5 ۶ 99/2015

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