Can you help by answering this question?

What is an insulation resistance test?

15 views
in Electrical Machine by
A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ohm. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is

1 Answer

0 votes
by

A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ohm. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.87

Related questions

1 answer 36 views

A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is

asked May 3, 2018 in Electrical Machine by Shimroz123
1 answer 30 views

Aluminium is not used as winding wire for the armature of a dc machine because  (1) aluminium has low resistivity (2) a large winding space is taken by aluminium conductors and creates jointing problems (3) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper

asked Apr 29, 2018 in Electrical Machine by Shimroz123
1 answer 16 views

The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is  (1) 1000V (2) 100V (3) 600V (4) 10,000V

asked Apr 29, 2018 in Electrical Machine by Shimroz123
1 answer 45 views

Why is the armature of DC generator laminated?

asked Mar 3, 2018 in Electrical Machine by Quiz
1 answer 39 views

The normal value of the armature resistance of a d.c. motor is?

asked Mar 26, 2018 in DC motor by Shimroz123
1 answer 27 views

In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as  (1) synchronous motor (2) synchronous generator (3) asynchronous motor (4) asynchronous generator

asked May 1, 2018 in Electrical Machine by Shimroz123
1 answer 28 views

The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

asked Apr 29, 2018 in Electrical Machine by Shimroz123
1 answer 15 views

In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is :

asked Apr 29, 2018 in Electrical Machine by Shimroz123
1 answer 24 views

The armature reaction in a synchronous generator supplying leading power factor load is (A) magnetizing (B) demagnetizing (C) demagnetizing and cross-magnetizing (D) magnetizing and cross-magnetizing

asked Apr 28, 2018 in Electrical Machine by Shimroz123
1 answer 15 views

The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be?

asked Mar 21, 2018 in DC generator by Shimroz123
1 answer 32 views

A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively

asked May 3, 2018 in Electrical Machine by Shimroz123
2 answers 43 views

In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

asked May 1, 2018 in Electrical Machine by Shimroz123
1 answer 17 views

In a dc machine, interpoles are used to  (1) neutralize the effect of armature reaction in the interpolar region (2) generate more induced emf in the armature (3) avoid interference of the armature flux with the main -field flux (4) reduce the demagnetizing effect of armature reaction

asked Apr 29, 2018 in Electrical Machine by Shimroz123
1 answer 32 views

The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is :  (A) 256 W (B) 320 W (C) 500 W (D) 625 W

asked Apr 30, 2018 in Switchgear And Protection by Shimroz123
1 answer 55 views

A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly?

asked Mar 21, 2018 in DC generator by Shimroz123
2 answers 34 views

The fall in speed of a dc generator due to increase in load can be corrected by  (1) cooling the armature.. (2) increasing the excitation. (3) reducing the load voltage. (4) increasing the input to the prime mover

asked May 1, 2018 in Electrical Machine by Shimroz123
1 answer 18 views

In a DC generator the windings of interpoles are connected :  (A) in series with main field winding, to create a pole,of same polarity as the main pole ahead in the direction of rotation.  (B) in series with main field winding, to create a pole of opposite polarity as the main pole ahead in the direction of ... in the direction of rotation.  (D) in series with the armature winding, to create a pole of opposite polarity as the main pole ahead in the direction of rotation.

asked Apr 29, 2018 in Electrical Machine by Shimroz123
2 answers 55 views

Armature control of DC motor

asked Aug 9, 2017 in Electrical Machine by Zeeshan
1 answer 109 views

What is the difference between an AC and DC generator?

asked Mar 15, 2018 in Electrical Machine by Quiz
0 answers 23 views

What is the principle of DC generator?

asked Mar 15, 2018 in Electrical Machine by Quiz
1 answer 31 views

Brushes of DC machine are made up of ?

asked Mar 3, 2018 in Electrical Machine by Quiz
1 answer 17 views

For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ?

asked Mar 20, 2018 in DC generator by Shimroz123
1 answer 36 views

From which material field coils of DC generator are made of?

asked Mar 3, 2018 in Electrical Machine by Quiz
1 answer 17 views

The magnetic neutral plane shifts in a dc machine (A) in the direction of motion of motor (B) in the direction of motion of generator (C) due to increase in the field flux (D) cause reduction of flash over between commutator segments

asked Apr 28, 2018 in Electrical Engineering by Shimroz123
1 answer 32 views

What is the percentage of stray losses in DC machine?

asked Mar 8, 2018 in Electronics Engineering by Quiz
1 answer 23 views

The terminal characteristics of a dc generator suitable for electric welders is (A) separately excited generator (B) shunt generator (C) series generator (D) differentially compounded generator

asked Apr 28, 2018 in Electrical Engineering by Shimroz123
0 answers 17 views

A DC shunt generator supplies 450 A at 230 V. The resistances of shunt field and armature are 50 Ω and 0.025 Ω respectively. What will be the armature voltage drop?  (A) 11.24 V (B) 22.7 V (C) 31.6 V (D) 38.4 V 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 91 views

Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as?

asked Mar 25, 2018 in Basic concepts by Shimroz123
1 answer 27 views
1 answer 20 views

 If shunt generator delivers 100 A at 200 V, and the resistance of the shunt field and armature are 100 ohm and 0.01 ohm respectively, the generated e.m.f. will be : -  a) 212 V b) 205 V c) 210 V d) 201.02 V

asked Apr 11, 2018 in Electrical Engineering by Shimroz123
0 answers 26 views

A 200 V dc motor takes a field current of 2 A to generate a back emf of 180 V. If the field winding resistance is 80 Ω, the resistance of the shunt field regulator is (A) 10 Ω (B) 20 Ω (C) 100 Ω (D) 180 Ω

asked Jun 4, 2018 in Electrical Machine by Shimroz123
1 answer 14 views

Welcome to electronics2electrical.com here you can ask questions related to electrical, electronics, mechanical, telecommunication, instrumentation, computer, mathematics, physics etc.
Be respectful to all the members. Do not copy and paste the answers from other websites which have copyright content. While asking question give full details about it.

Categories

Most popular tags

power motor dc circuit transformer voltage current used system phase resistance factor synchronous load ac energy induction electric generator series frequency between speed capacitor use electrical meter line difference control type mosfet transmission magnetic plant high single instrument bjt unit source advantages function diode and machine winding field define torque parallel amplifier supply shunt thyristor motors electricity arduino maximum time relay armature problem value on transformers types coil diagram state flow ratio material three formula starting direction theorem method emf operating efficiency digital wave microprocessor test instruments inductance loss measure operation connected signal low applications effect single-phase network temperature working constant losses different law wattmeter measuring compare controlled breaker drive device logic rc full switch flux wire resistivity disadvantages free of materials machines angle force converter conductor transistor gain open protection scr core measurement number bridge principle generators reactance circuits negative the friction iron loop short pole battery conservation steam resistors hysteresis computer using analog lines secondary station gate a rectifier inverter linear induced relays nuclear capacitance basic characteristics design direct work rotor electronics ammeter forces diesel damping rlc connection factors capacitors minimum insulation moving regulation running self systems air fault range main stability quality starter igbt eddy alternator ideal rl average 3-phase plants arc thermal error fuzzy biasing dielectric pressure balanced superposition errors copper rotation feedback impedance measured electronic electrons charge inductive transfer explain start off back curve over solar is three-phase tariff locomotive peak bias zener engineering commutator surge conductors rating universal potentiometer density permanent mechanical transducer capacity memory adc excitation two fuse pure harmonics application semiconductor inductor internal pmmc reaction welding resonance traction permeability breakers rms designed electromagnetic si generation brushes switching capacitive shaded rate 1 distribution resistor methods delta star oscillator reluctance simplification algebra 8085 boolean weston dynamometer insulating strength installation definition fuel heating earth units
...