ELECTRICAL ENGINEERING BITS-2

101.

Which of the following is the best method for determining the stability and transient response ?
 Nyquist plot 

102.

In cables the charging current
 leads the voltage by 90° 

103.

The arcing contacts in a circuit breaker are made of
 copper tungsten alloy 

104.

Two windings provided on the stator of 1-phase induction motor, one main winding and the other auxiliary winding are connected ?

 in parallel

105.

By which of the following the control action is determined when a man walks along a path ?

 Eyes

106.

In a synchronous motor electromagnetic power varies ??
 directly as applied voltage 

107.

In force-voltage analogy, velocity is analogous to
 current 

108.

________has tendency to oscillate.
 Closed loop system 

109.

Which of the following method is used for changing power factor from leading to lagging shunt capacitor ??
 shunt reactor 

110.

In shaded pole induction motors, the flux moves from ------------- region to ----------------- region respectively?
 unshaded, shaded 

111.

Equalizer rings are used in which of the followings?

 lap winding

112.

Stability of a transmission line can be increased by ________?
 shunt capacitor and series capacitor 

113.

A 4 bus power system consists of 4 transmission lines, then find the sparsity of Y bus matrix?

 0.25

114.

Low frequency supply is necessary for direct core type induction furnaces because ___

With normal frequeny supply the electromagnetic forces causes severe stirring action in the molten metal. 
 Both of these

115.

In resistance heating highest working temperature is obtained from heating elements made of
 nichrome 

116.

No load saturation characteristics are plotted between ____________??

 no load voltage and field current

117.

Addition of zeros in transfer function causes which of the following ?

 Lag-compensation

118.

A 3 phase stepper motor has 6 stator poles and 4 rotor poles, then find the step angle?
 30° 

119.

What is the ressistance of a bulb having a rating of 420 volt and 300 watt
 588 

120.

Induction ening is possible in case of _______

 AC supply only.

121.

Find the number of strands of ACSR conductor for 3 layer transmission line?
 19 

122.

Which of the following motor has the highest power factor at full load?

 capacitor run

123.

Which of the following statement is true _______
 At higher voltage, cost of transmission is increased 
 At higher voltage, cost of transmission is reduced

124.

In a single phase power factor meter the phase difference between the currents in the two pressure coils is

 exactly 90°

125.

A reluctance motor

 is compact

126.

The disadvantage with paper as insulating material is
 it is hygroscopic 

127.

In inducting heating, which of following is of high value?
 Frequency. 

128.

Spring constant in force-voltage analogy is analogous to

 reciprocal of capacitance

129.

To eliminate the 5th harmonic in the induced voltages their respective pitch factor angle should be ??
 36° 

130.

An alternator is feeding an infinite busbar. Its prime mover suddenly shutdown. The alternator will
 continue to work as synchronous motor with same direction of rotation 

131.

Volt box is a component to

 extend voltage range

132.

Which of the following can be measured by LVDT?
 All of these 

133.

In a low power factor wattmeter the pressure coil is connected

 to the load side of the current coil

134.

Single phase induction motors are
 started using capacitor or inductor or both , 

135.

Which motors are preferred for refrigeration and air conditioning in smaller units?
 Induction motors. 

136.

The function of shunt in an ammeter is to
 by pass the current 

137.

In direct arc furnace, which of the following has high value ?
 Current 

138.

________technique is not applicable to nonlinear system ?

 Nyquist Criterion

139.

Under over excitation synchronous phase modifier works as ______?

 shunt capacitor

140.

The disc of an instrument using eddy current damping should be of

 conducting and non-magnetic material

141.

If we increase the spacing between the phase conductors, the value of line inductance _______

 increase

142.

Which type of single phase induction motor is having the highest power factor at full load ?
 Capacitor run type. 

143.

For arc heating, the electrodes used are made of __________

 Graphite.

144.

While selecting an electric motor for a floor mill, which electrical characteristics will be of least significance ?
 Braking 

145.

Brushes are always placed on--------------- , in order to achieve sparkles commutation?
 MNA 

146.

Transmission line parameters of the short transmission line are __________
 1,Z,0,1 

147.

The diameter of the rotor shaft for an electric motor depends on which of the following ?
 Horse power and r.p.m. 

148.

In an electric room heat converter the method of heating used is ________
 Resistance heating. 

149.

Induction heating takes place on which of the following ?
 Conducting materials which may or may not be magnetic 

150.

If an inductance is connected in one arm of bridge and resistances in the remaining three arms

 the bridge cannot be balanced

151.

A good control system has all the following features except
 slow response 

152.

Which of the following braking systems on the locomotives is costly ?
 Regenerative braking on electric locomotives 

153.

Reversing the direction of rotation of split phase motors is done by _______?

interchanging the capacitor from starting winding to main winding or vice versa 

154.

An increase in gain, in most systems, leads to
 smaller damping ratio 

155.

In a Weston frequency meter, the magnetic axes of the two fixed coils are
 perpendicular 

156.

A four quadrant operation requires
 two full converter connected in back to back. 

157.

For given maximum axle load tractive efforts of AC. locomotive will be
 more than that of D.C. locomotive 

158.

The converse of ness is known as
 softness 

159.

Which of the following drives is suitable for mines where explosive gas exists ?
 Battery locomotive 

160.

The bedding on a cable consists of
 all of these 

161.

Which of the following materials is used in the manufacture of resistance grids to be used in the starters of large motors ?

 Cast-iron

162.

Ferranti effect will not occur in which of the following transmission lines_____?
 short transmission lines 

163.

In self cooled motors the cooling time constant is about ______ than the heating time constant because cooling conditions are worse at standstill.

 2 to 3 times greater

164.

Compensating winding is placed in the ______?

 pole shoe

165.

SF6 gas
 is nontoxic 

166.

Disc windings are primarily used in

 high capacity transformers

167.

Velocity error constant of a system is measured when the input to the system is unit _______ function.

 ramp

168.

In case of steam engines the steam pressure is

 10 to 15 kgf/cm^2

169.

Standard resistor is made from
 maganin 

170.

Basically a potentiometer is a device for

 comparing two voltages

171.

From which of the following transfer function can be obtained ?

 Signal flow graph

172.

_________is preferred for automatic drives.

 Ward-Leonard controlled D.C. motors

173.

Due to which of the following reasons aluminium does not corrode in atmosphere ?

 Atmospheric oxygen can only diffuse very slowly through the oxide layer which is formed on the surface of aluminium

174.

A certain cable has an insulation of relative permittivity 4. If the insulation is replaced by one of relative permittivity 2, the capacitance of the cable will become

 one half

175.

The power developed by salient pole synchronous machine is/are
 both of these 

176.

_______ was the first city in India to adopt electric traction.

 Bombay

177.

In triangular configuration, inductance and capacitance values are ------ and ------ respectively

 less, higher

178.

The operating voltage of a meggar is about
 100 V 

179.

Stability of a transmission line can be increased by ______?

 series capacitor and shunt capacitor

180.

The functions of inter poles are ____?

 Both of these

181.

For intermittent work which of the following furnace is suitable?
 Indirect arc furnace. 

182.

In an automatic control system which of the following elements is not used ?
 Oscillator 

183.

The intersheaths in the cables are used to

 provide proper stress distribution

184.

'Load' in terms of transformer means:

 Current in secondary

185.

The scale of a rectifier instrument is
 linear 

186.

In graphite, bonding is
 Vander Waals and covalent 

187.

Condition for maximum voltage regulation ___________

 tanf = X/R

188.

Four wires of same material, the same cross-sectional area and the same length when connected in parallel give a resistance of 0.25 Q. If the same four wires are connected is series the effective resistance will be:
 4 Q 

189.

Which braking is not possible in series motor?

 Regenerative braking.

190.

Arc drawn between two electrodes produces heat has a temperature ?

 Between 1000-3500°C.

191.

With feed back _____ reduces.

 system gain

192.

Type of single phase motor having highest power factor at full load is
 capacitor run. 

193.

In which of the following motors DC excitation is not required?

 reluctance motor

194.

In arc furnace the function of choke is

 to stabilize the arc

195.

Which of the following alternators contain large number of poles?
 hydro alternators 

196.

The normal value of adhesion friction is

 0.25

197.

The power factor of a single phase load can be calculated if the instruments available are

 one voltmeter, one ammeter and one wattmeter

198.

While operating on variable frequency supplies, the AC motor requires variable voltage in order to _______?
 avoid effect of saturation. 

199.

A conditionally stable system exhibits poor stability at
 reduced values of open loop gain