Q.236 The most commonly used material for insulators of overhead lines is
A. porcelain
B. Glass
C. Steatite
D. none of the above
Ans.: A
Q.237 Sag is provided in overhead lines so that
A. Safe tension is not exceed
B. repair can be made
C. conductor material is saved
D. none of the above
Ans.: A
Q.238 By increasing the clearance spacing between the phases of the transmission lines Corona Discharge effect__
A. increases
B. reduces
C. remains the same
D. none of the above
Ans.: B
Q.239 The diversity factor is always
A. equal to 1
B.less than 1
C greater than 1
D. none f the above
Ans.: C
Q.240 In a d.c 2-wire feeder the voltage drop per wire is 2.5%. The transmission efficiency of the feeder is
A. 97.50%
B. 95%
C. 93.75%
D. 98.75%
Ans.: B
Q.241 Unit of reactive power is
A. VA
B. Watt
C. VAR
D. Ohm
Ans.: C
Q.242 To increase the capacity of a transmission line for transmitting power which of the following must be decreased?
A. Capacitance
B. Line inductance
C. Voltage
D. all of the above
Ans.: B
Q.243 2KWh = ____kcal
A. 610
B. 756
C. 520
D. 860
Ans.: D
Q.244 ____ will work only on d.c supply
A. electric lamp
B. Refrigerator
C. Heater
D. Electroplating
Ans.: D
Q.245 As a matter of economy, voltage for power transmission should be
A. low
B. medium
C. high
D. none of the above
Ans.: C
Q.246 The resolution of an instrument is the
A. minimum quantity it can measure
B. maximum quantity it can measure
C. maximum non linearity
D. none of the above
Ans.: A
Q.247 The capital cost of a power plant depends on
A. total installed capacity only
B. total number of units only
C. total installed capacity and number of units as well
D. neither the installed capacity nor number of units
Ans.: C
Q.248 Which of the distribution system is used for balanced loads?
A. 1-phase, 2-wire system
B. 3-phase, 4-wire system
C. 3-phase, 3-wire system
D. none of the above
Ans.: C
Q.249 The principle of dynamically induced emf is utilized in
A. transformer
B. choke
C. generator
D. thermocouple
Ans.: C
Q.250 The amount of copper in the primary is___ that of secondary.
A. about the same as
B. greater than
C. smaller than
D. none of the above
Ans.: A