menu search
person
thumb_up_alt 0 like thumb_down_alt 0 dislike
83 views

1 Answer

For handling greater currents induction wattmeters are used in conjunction with current transformers.

thumb_up_alt 0 like thumb_down_alt 0 dislike
← Prev Question Next Question →

Related questions

Description :

Answer :

The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a two-phase winding.

thumb_up_alt 0 like thumb_down_alt 0 dislike
131 views 1 answer
Description :

State starters used for i) 3-Ph squirrel cage induction motor (3HP) ii) D.C. motor 

Answer :

Name the starters used for following motors : i) 3 H.P. 3-Ph squirrel cage I.M: i) DOL starter OR ii) Star-Delta Starter OR ii) Auto transformer starter OR iii) Soft start starter.  ii) D.C Shunt Motor : 1) Armature resistance starter (Three Point Starter) OR 2) Four Point Starter 

thumb_up_alt 0 like thumb_down_alt 0 dislike
125 views 1 answer
Description :

The range of frequencies used in induction heating is :  (A) 0-25 Hz  (C) less than 200 Hz  (B) 50 to 100 Hz  (D) more than 1 kHz

Answer :

The range of frequencies used in induction heating is : more than 1 kHz

thumb_up_alt 0 like thumb_down_alt 0 dislike
76 views 1 answer
Description :

Answer :

In a single phase power factor meter the phase difference between the currents in the two pressure coils is exactly 90°.

thumb_up_alt 0 like thumb_down_alt 0 dislike
195 views 1 answer
Description :

Answer :

The repulsion-start induction-run motor is used because of high starting torque.

thumb_up_alt 0 like thumb_down_alt 0 dislike
66 views 1 answer
Description :

The transient currents are associated with the?

Answer :

The transient currents are associated with the changes in the stored energy in the inductors and capacitors.

thumb_up_alt 0 like thumb_down_alt 0 dislike
56 views 1 answer
Description :

Answer :

Eddy currents are induced in the pole shoes of a D.C. machine due to relative rotation between field and armature.

thumb_up_alt 0 like thumb_down_alt 0 dislike
154 views 1 answer
Description :

How eddy currents are generated?

thumb_up_alt 0 like thumb_down_alt 0 dislike
64 views 0 answers
Description :

Explain following techniques related to energy conservation in transmission and distribution system. (i) By balancing phase currents (ii) Variable technical losses (I2R losses).

Answer :

(i) Balancing Phase currents: Proper (healthy balanced) three phase loads always draw equal currents in all lines but single phase loads in the 3 phase 4 wire system or loads connected between two ... . 11) Minimize I2R losses. 12) Balance the load currents. 13) Regulate the system voltages.

thumb_up_alt 0 like thumb_down_alt 0 dislike
117 views 1 answer
Description :

Answer :

Interruption of large currents by relay requires arc suppressing blow out coils, wide separation of the opened contacts, high speed opening of contacts.

thumb_up_alt 0 like thumb_down_alt 0 dislike
69 views 1 answer
Description :

Answer :

An induction wattmeter can be used for A.C. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
78 views 1 answer
Description :

An induction type energy meter is found to run fast. Correction for this error can be made by  (A) Over-load compensation. (B) Voltage compensation. (C) Moving the brake magnet away from the centre of the disc. (D) Moving the brake magnet towards the centre of the disc.

Answer :

An induction type energy meter is found to run fast. Correction for this error can be made by Moving the brake magnet away from the centre of the disc.

thumb_up_alt 0 like thumb_down_alt 0 dislike
112 views 1 answer
Description :

Permanent magnet moving coil instruments are used for

Answer :

PMME are mostly used for measuring voltage and current.

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.6k views 2 answers
Description :

Answer :

Induction type single phase energy meters measure electric energy in kWh.

thumb_up_alt 0 like thumb_down_alt 0 dislike
281 views 1 answer
Description :

Answer :

An induction meter can handle current up to 100 A.

thumb_up_alt 0 like thumb_down_alt 0 dislike
90 views 1 answer
Description :

Answer :

Commonly used instruments in power system measurement are induction.

thumb_up_alt 0 like thumb_down_alt 0 dislike
77 views 1 answer
Description :

State the function and shape of following parts used in induction type energy meter: i) Series magnet ii) Shunt magnet iii) Al disc iv) Brake magnet

Answer :

i) Series magnet: produce flux proportional to current (load current) of circuit and interact in the aluminum disc with flux produced by voltage magnet for torque production. Its shape is like letter U.  ii) ... : brakes the motion of the aluminum disc or slows it down. Its shape is like letter C. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
80 views 1 answer
Description :

Eddy current damping cannot be used for moving iron instrument because

Answer :

Eddy current damping cannot be used for moving iron instrument because the presence of a permanent magnet required for such purpose would affect the deflection and hence the reading of the instrument

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.2k views 1 answer
Description :

Answer :

if induction motor rotates exceed than its synchronous speed, it acts as a generator.

thumb_up_alt 0 like thumb_down_alt 0 dislike
54 views 1 answer
Description :

Answer :

A phase shifting transformer is used in conjunction with Drysdale potentiometer.

thumb_up_alt 0 like thumb_down_alt 0 dislike
144 views 1 answer
Description :

In a split-phase induction motor, the resistance/reactance ratios of windings are such that (A) current in the auxiliary winding leads the current in the main winding (B) current in the auxiliary winding lags the current in the main winding (C) both windings develop the same starting torque (D) both windings develop high starting current

Answer :

In a split-phase induction motor, the resistance/reactance ratios of windings are such that current in the auxiliary winding leads the current in the main winding

thumb_up_alt 0 like thumb_down_alt 0 dislike
84 views 1 answer
Description :

Slot harmonics are reduced in induction motors by using (A) fractional-pitch windings (B) fractional-slot windings (C) integral-slot windings (D) distributed windings

Answer :

Slot harmonics are reduced in induction motors by using fractional-slot windings

thumb_up_alt 0 like thumb_down_alt 0 dislike
67 views 1 answer
Description :

Answer :

The rotor slots, in an induction motor, are usually not quite parallel to the shaft because it helps in reducing the tendency of the rotor teeth to remain under the stator teeth.

thumb_up_alt 0 like thumb_down_alt 0 dislike
124 views 1 answer
Description :

List any four errors in induction type energy meter. Give method of compensation for each.

Answer :

Errors in Induction Type Energy Meter with their Compensation:  1) Error due to friction: This error can be compensated by the additional shading band provided on the shunt electromagnet.  2) Phase ... error: This error can be compensated by providing a flux diverter' to the current magnet. 

thumb_up_alt 0 like thumb_down_alt 0 dislike
997 views 1 answer
Description :

With a neat sketch give the working of shaded pole induction motor.

Answer :

Explanation: It has squirrel cage rotor and salient pole stator. The stator poles are shaded partially by short circuited conductor band to create the phase difference between the fluxes emerging from shaded ... rotating magnetic field in the air-gap and torque is exerted on the squirrel cage rotor.

thumb_up_alt 0 like thumb_down_alt 0 dislike
143 views 2 answers
Description :

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.

thumb_up_alt 0 like thumb_down_alt 0 dislike
94 views 0 answers
Description :

With a neat diagram explain doubly fed induction generator (DFIG). 

Answer :

Diagram of Doubly fed induction generator (DFIG):  Explanation :-  DFIG can feed power through the stator as well as rotor to the grid. The stator is directly connected to the fixed frequency ... voltage is 690 V AC. So it must be step up to 33 KV to connect to power grid.  

thumb_up_alt 0 like thumb_down_alt 0 dislike
5.1k views 1 answer
Description :

A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will?

Answer :

A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will not start at all.

thumb_up_alt 0 like thumb_down_alt 0 dislike
124 views 1 answer
Description :

A dummy strain gage is used in a quarter bridge strain gage circuit to :  (A) compensate for changes in temperature and lead wire resistance  (B) produce more output voltage from the bridge  (C) increase the sensitivity of the bridge  (D) compensate lead wire resistance only

Answer :

A dummy strain gage is used in a quarter bridge strain gage circuit to : compensate for changes in temperature and lead wire resistance 

thumb_up_alt 0 like thumb_down_alt 0 dislike
82 views 1 answer
Description :

An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be  (1) unaffected (2) decreased (3) increased (4) either decreased or increased depending on the direction of the DC field

Answer :

An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be either decreased or increased depending on the direction of the DC field

thumb_up_alt 0 like thumb_down_alt 0 dislike
277 views 1 answer
Description :

Explain energy conservation technique “by improving power quality” for induction motor.

Answer :

Energy conservation method in induction motor by improving power quality: Electrical energy can be conserved by improving the power quality. It can be achieved by avoiding voltage unbalance, maintaining ... losses can be minimized by using harmonic filter thus reducing the harmonics in the system.

thumb_up_alt 0 like thumb_down_alt 0 dislike
3.0k views 2 answers
Description :

A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for

Answer :

A 400 V, 50 Hz three-phase induction motor rotates at 1440 rpm on full -load. The motor is wound for 4 poles

thumb_up_alt 0 like thumb_down_alt 0 dislike
157 views 1 answer
Description :

Why starter is required for starting an induction motor?

thumb_up_alt 0 like thumb_down_alt 0 dislike
102 views 0 answers
Description :

Answer :

Yes, Induction heating is used for both magnetic and non-magnetic materials.

thumb_up_alt 0 like thumb_down_alt 0 dislike
87 views 1 answer
Description :

Piezoelectric Transducer is used to measure  (1) displacement (2) resistance (3) current (4) temperature

Answer :

Piezoelectric Transducer is used to measure displacement 

thumb_up_alt 0 like thumb_down_alt 0 dislike
63 views 1 answer
Description :

Which of the following can be used to measure the capacitance of a capacitor? A) Rheostat B) Schering bridge C) Wheatstone bridge D) None of these

Answer :

Which of the following can be used to measure the capacitance of a capacitor? A) Rheostat B) Schering bridge C) Wheatstone bridge D) None of these

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.7k views 1 answer
Description :

Answer :

Commonly used standard capacitor is concentric cylindrical type.

thumb_up_alt 0 like thumb_down_alt 0 dislike
69 views 1 answer
Description :

What type of meter is used to measure current?

Answer :

Ammeter

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.7k views 3 answers
Description :

What equipment is used to measure voltage?

Answer :

Voltmeter is used to measure voltage.

thumb_up_alt 0 like thumb_down_alt 0 dislike
197 views 2 answers
Description :

Regulating-transformers are used in power systems for control of

Answer :

Regulating-transformers are used in power systems for control of power flow

thumb_up_alt 0 like thumb_down_alt 0 dislike
128 views 1 answer
Description :

Answer :

Starters are used with D.C. motors because to restrict armature current as there is no back e.m.f. while starting.

thumb_up_alt 0 like thumb_down_alt 0 dislike
73 views 1 answer
Description :

Surge absorbers are used for protection against

Answer :

Surge absorbers are used for protection against low voltage high frequency oscillations

thumb_up_alt 0 like thumb_down_alt 0 dislike
3.0k views 1 answer
Description :

Answer :

D.C. shunt motors are used for driving machine tools.

thumb_up_alt 0 like thumb_down_alt 0 dislike
73 views 1 answer
Description :

Answer :

The inverse definite mean time relays are used for over current and earth fault protection of transformer against internal short-circuits.

thumb_up_alt 0 like thumb_down_alt 0 dislike
2.5k views 1 answer
Description :

Answer :

The single phasing relays are used for the protection of three phase motors.

thumb_up_alt 0 like thumb_down_alt 0 dislike
161 views 1 answer
Description :

Answer :

Impedance relays are used for phase faults on long line.

thumb_up_alt 0 like thumb_down_alt 0 dislike
68 views 1 answer
Description :

What are digital signals used for?

thumb_up_alt 0 like thumb_down_alt 0 dislike
57 views 0 answers
Description :

Answer :

Transformer coupled amplifiers Direct coupled amplifiers Multistage amplifiers Darlington amplifiers Emmiter follower

thumb_up_alt 1 like thumb_down_alt 0 dislike
77 views 1 answer
Description :

State the function of following parts in Induction motor. (i) Stator (ii) Slip rings

Answer :

Name of part Function Stator 1) Stator frame supports the core, terminal box and protects the inner parts. 2) Stator core houses stator winding. 3) Stator winding ... ) Provides facility to connect external resistance to rotor circuit through brushes for starting and control.

thumb_up_alt 0 like thumb_down_alt 0 dislike
72 views 1 answer
Description :

List the energy conservation technique in induction motor. 

Answer :

Following are the list of energy conservation techniques in electrical motors: 1) Reduction in iron losses by using low loss silicon steel core material laminated to thinner dimension. 2) Using bigger length ... at light load. 13) By rewinding in induction motor 14) By motor survey

thumb_up_alt 0 like thumb_down_alt 1 dislike
83 views 1 answer
...