Question is ⇒ In hazardous area of gassy mines, material transportation is done by vehicles powered by, Options are ⇒ (A) A.C. mains, (B) D.C. mains, (C) I.C. engines, (D) batteries, (E) , Leave your comments or Download question paper.

Question is ⇒ In hazardous area of gassy mines, material transportation is done by vehicles powered by, Options are ⇒ (A) A.C. mains, (B) D.C. mains, (C) I.C. engines, (D) batteries, (E) , Leave your comments or Download question paper. Previous question Next question


Q1.	In hazardous area of gassy mines, material transportation is done by vehicles powered by
A.	A.C. mains [Wrong Answer]
B.	D.C. mains [Wrong Answer]
C.	I.C. engines [Wrong Answer]
D.	batteries [Correct Answer]
View Answer 7 -2 Explanation:- Answer : D Discuss it below : !! OOPS Login [Click here] is required to post your answer/result Help other students, write article, leave your comments

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⇒ A series motor is' best suited for driving
machine tools
cranes and hoists
shear and punches
none of the above

⇒ The variable resistor shunting the field of a D.C. series motor is called a
armature divertor
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field divertor
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⇒ Which of the following steps is likely to result in reduction of hysteresis loss in a D.C. generator ?
Providing laminations in armature core
Providing laminations in stator
Using non-magnetic material for frame
Using material of low hysteresis coefficient for armature core material

⇒ Which D.C. motor has got maximum self loading property?
Series motor
Shunt motor
Cumulatively compounded motor
Differentially compotinded motor

⇒ The ratio of starting torque to fullload torque is least in case of
series motors
shunt motors
compound motors
none of the above

⇒ What will happen if supply terminals of D.C. shunt motor are interchanged ?
The direction of rotation will reverse
Motor will stop
Motor will run at speed lower than the normal speed in the same direction
Motor will run at its normal speed in the same direction as it was running

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⇒ Which of the following tests can be used to determine no-load losses in a D.C. shunt motor ?
Running down test
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⇒ Voltage equation for D.C. motor is
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shunt, compound and series motors
all D.C. motors

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1

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synchronous motor
d.c. series motor

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constant voltage drive
constant current drive
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the brushes
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Retardation test
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⇒ For constant torque drive which speed control method is preferred ?
Field control
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⇒ Which of the following tests will be suitable for testing two similar D.C. series motors of large capacity ?
Swinburne's test
Hopkinson's test
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Brake test

⇒ Which of the following can be used to control the speed of a D.C. motor ?
Thermistor
Thyristor
Thyratron
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few number of turns of thin wire

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back e.m.f. as well as current drawn both decrease
back e.m.f. decreases and current drawn increases

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