ELECTRICAL ENGINEERING MCQ_13

Q.206 Air blast circuit breaker is used for
A. Short duty

B. Over currents

C. Repeated duty

D. Intermittent duty
Ans.: C

Q.207 _______ has zero temperature co-efficient of resistance
A. Carbon

B. Aluminium

C. Porcelain

D. Manganin
Ans.: D

Q.208 A star circuit has element of resistance R/2. The equivalent delta elements will be
A. R/6

B. 2R

C. 3R/2

D. 4R
Ans.: C

Q.209 The peak value of sine wave is 200 V. Its average value is
A. 141.4 V

B. 282.8 V

C. 200 V

D. 127.4 V
Ans.: D

Q.210 The conductors of the overhead lines are
A. Stranded

B. Solid

C. Both (A) and (B)

D. None of the above
Ans.: A

Q.211 The power transmitted will be maximum when
A. Reactance is high

B. Corona losses are minimum
C. Receiving end voltage is more

D. Sending end voltage is more
Ans.: D

Q.212 The current drawn by the line due to corona losses is
A. Non-sinusoidal

B. sinusoidal

C. Square

D. Triangular
Ans.: A

Q.213 In a tap changing transformer, the tapping are provided on
A. Primary winding

B. High voltage winding

C. Secondary winding

D. Any of the above
Ans.: B

Q.214 Load factor of power station is generally
A. Equal to unity

B. Less than unity

C. More than unity

D. Equal to zero
Ans.: B

Q.215 The minimum dielectric stress in a cable is at
A. Bedding

B. Armour

C. Conductor surface

D. Lead sheath
Ans.: D

Q.216 The surge resistance of cable is
A. 100 Ω

B. 5Ω

C. 20 Ω

D. 50 Ω
Ans.: D

Q.217 If the length of cable is doubled, its capacitance
A. Becomes doubled

B. Becomes one-fourth

C. Becomes one-half

D. Remains unchanged
Ans.: A

Q.218 A 6 pole lap wound armature has 1200 conductors and flux per pole of 0.01 wb. If the emf generated is 100 V, the machine is driven at a speed of
A. 1200 rpm

B. 100 rpm

C. 600 rpm

D. 500 rpm
Ans.: D

Q.219 Corona results in
A. Better regulation

B. Radio Interference

C. Power factor Improvement

D. none of the above
Ans.: B

Q.220 Which of the following motors is inherently self starting?

A. Split phase motor

B. Reluctance motor

C. Shaded pole motor

D. None of the above

Ans.: C