Please Log in or Register for more.


499 views

1 Answer

Answer :

In case of D.C. machines, mechanical losses are primary function of speed.

Like 0 like

Please log in or register to answer this question.

Related Questions



Last Answer : Iron losses in a D.C. machine are independent of variations in load.

Show More

161 views 1 answer








Last Answer : In a D.C. generator, the iron losses mainly take place in armature rotor.

Show More

273 views 1 answer








Last Answer : The total losses in a well designed D.C. generator of 10 kW will be nearly 500 W.

Show More

138 views 1 answer







Losses which occur in rotating electric machines and do not occur in transformers are?
Last Answer : Friction losses windage losses 

Show More

208 views 2 answers







Briefly explain how an electrical generator converts mechanical energy into electrical energy.
Last Answer : Working principle of DC generator: * Working principle of DC generator is the principle of dynamically induced emf or electromagnetic induction. * According to this principle, when flux is cut by a conductor, an ... , the flux is cut by the armature winding and an emf is dynamically induced in it. 

Show More

350 views 2 answers







Explain the suitability of aluminium as an electrical conductor with respect to its mechanical and electrical properties. 
Last Answer : Following are requirements of conductor:- i) High conductivity :  Material should have high conductivity, So that * cross section of conductor (size) reduces, * Copper losses reduces, * So Efficiency ... . Boiling point is 1820°C 9. Specific gravity is 2.7 10. High resistance to corrosion. 

Show More

213 views 1 answer







Define natural, mechanical, forced and induced draught systems.
Last Answer : Natural draught system: - When the fuel is burnt (combustion) in the furnace due to natural circulation of air, the draught is called natural draught. Mechanical draught system: -  In a mechanical ... combustion. OR If fan/blower is placed after the furnace then it is called as induced draught

Show More

91 views 1 answer







Explain the mechanical properties of insulating materials.
Last Answer : i) Mechanical strength: Mechanical strength depends on temperature and humidity. a) Temperature: High temperature badly affects the mechanical strength of insulating material. While selecting material ... material should have property of easy moulding and machined into required shape and size.

Show More

131 views 1 answer







Which of the following converts linear displacement from a mechanical reference into a proportional electrical signal containing phase and amplitude information? A) CRO B) LVDT C) RVDT D) None of these
Last Answer : Which of the following converts linear displacement from a mechanical reference into a proportional electrical signal containing phase and amplitude information? A) CRO B) LVDT C) RVDT D) None of these

Show More

111 views 1 answer







In Torque-Voltage analogy, the Moment of Inertia of a mechanical rotational system is analogous to (A) Capacitance C. (B) Inductance L. (C) Resistance R. (D) Inductive reactance XL
Last Answer : In Torque-Voltage analogy, the Moment of Inertia of a mechanical rotational system is analogous to Inductance L.

Show More

725 views 1 answer







In a d.c. motor, the mechanical output power actually comes from?
Last Answer : In a d.c. motor, the mechanical output power actually comes from electrical input power.

Show More

1.2k views 1 answer







The mechanical power developed by the armature of a d.c. motor is equal to?
Last Answer : The mechanical power developed by the armature of a d.c. motor is equal to armature current multiplied by back e.m.f.

Show More

982 views 1 answer








Last Answer : The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is 0.5.

Show More

324 views 1 answer








Last Answer : As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for sound equipment.

Show More

115 views 1 answer







The synchronous motor which works on leading power factor and does not drive any mechanical load is called?
Last Answer : The synchronous motor which works on leading power factor and does not drive any mechanical load is called synchronous condenser.

Show More

162 views 1 answer







State the losses in secondary distribution system. 
Last Answer : The losses in secondary distribution system: a) Technical losses: 1. Due to poor voltage 2. Due to unbalance load 3. Due poor quality of transformer & its components 4. Due to poor quality ... of induction type of energy meter. 3. Lack of administration. 4. Energy theft 5. Unmetered supply

Show More

122 views 1 answer







Explain the “mitigation of power theft” and “faulty meter replacement” for energy conservation techniques to reduce commercial losses. 
Last Answer : Energy conservation techniques to reduce commercial losses:  1. Mitigation of Power Theft: Power theft being the most important issue which all of the service providing utilities ... agricultural sector. Prepaid meters may prove effective measures against unauthorized abstraction of energy. 

Show More

120 views 1 answer







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

Show More

194 views 1 answer







The friction losses in Real Transformers are :  (A) 0% (B) 5% (C) 25% (D) 50%
Last Answer : A

Show More

3.3k views 2 answers







Which of the following can reduce the Eddy current losses? A) By making the core of a stack of plates electrically insulated from each other B) By making the core of solid block C) By increasing the applied voltage  D) None of these
Last Answer : Which of the following can reduce the Eddy current losses? A) By making the core of a stack of plates electrically insulated from each other B) By making the core of solid block C) By increasing the applied voltage  D) None of these

Show More

90 views 1 answer







In DC motor iron losses are occurred in?
Last Answer : In DC motor iron losses are occurred in the armature.

Show More

138 views 1 answer







Reduction in core losses and increase in permeability are obtained with transformer employing?
Last Answer : Reduction in core losses and increase in permeability are obtained with transformer employing core built-up of laminations of cold rolled grain oriented steel.

Show More

615 views 1 answer







In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?
Last Answer : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are hysteresis and eddy current losses.

Show More

152 views 1 answer







Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is?
Last Answer : Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is approximately equal to 1.

Show More

160 views 1 answer







In a synchronous motor which losses varies with load?
Last Answer : In a synchronous motor, copper losses varies with load.

Show More

102 views 1 answer







Explain the electrical losses of magnetic materials used for the cores of inductors and transformer.

Show More

87 views 0 answers







What are the losses in a transmission line?

Show More

61 views 0 answers







What are the types of power losses in inductor?
Last Answer : Copper losses, Eddy current loss, and hysteresis loss are the types of power losses in inductor.

Show More

118 views 1 answer







What is the percentage of stray losses in DC machine?
Last Answer : Percentage of stray losses in DC machine is about 1 % .

Show More

115 views 1 answer







In synchronous motor, does the winding losses vary with load?
Last Answer : No, in the synchronous motor the winding losses do not vary with load.

Show More

512 views 1 answer








Last Answer : Iron loss, copper loss and mechanical losses these are the losses in DC machine.

Show More

118 views 1 answer







Explain the on state losses in power BJT.
Last Answer : On state losses in power BJT: Transistor have four types of losses one is turn on state losses second is turn off state losses third is turn on switching losses and fourth is turn ... ON = VCE sat x IC With increasing collector current collector to emitter saturation voltage increases.

Show More

295 views 1 answer







In case of D.C. machines, mechanical losses are primary function of (a) current (b) voltage (c) speed (d) none of above
Last Answer : Ans: c

Show More

41 views 1 answer













Why does my computer (Mac OSX) grumble when it's working?
Last Answer : answer:Hunger pangs? Bad hair day? Wants to go to the beach? Osteoarthritis? What’s the actual machine? Desk top? Lap top? How old? Which OS? The latest is 10.8.4, I think. Or it was a minute ago.

Show More

2 views 1 answer







What is the difference between basic hole and basic shaft ?
Last Answer : A basic hole is one whose lower deviation is zero and in case of basic shaft the upper deviation is zero.

Show More

3 views 1 answer







What is the percentage of carbon in cast iron ?
Last Answer : 2.5%.

Show More

3 views 1 answer







Anyone care to join me in a quiet prayer for Jeret "Speedy" Peterson?
Last Answer : Not to sound cold, but it won’t help at this point.

Show More

0 views 1 answer








Last Answer : Satisfactory commutation of D.C. machines requires brushes should be of proper grade and size, brushes should smoothly run in the holders, smooth, concentric commutator properly undercut.

Show More

106 views 1 answer








Last Answer : For a D.C. machines laboratory following type of D.C. supply will be suitable induction motor D.C. generator set.

Show More

115 views 1 answer








Last Answer : Brushes of D.C. machines are made of carbon.

Show More

87 views 1 answer








Last Answer : The purpose of retardation test on D.C. shunt machines is to find out stray losses.

Show More

74 views 1 answer







The design of mechanical parts is particularly important in case of _____ speed machines. (a) low (b) medium (c) high (d) any of the above
Last Answer : (c) high

Show More

9 views 1 answer








Last Answer : In a D.C. generator the number of mechanical degrees and electrical degrees will be the same when number of poles is 2.

Show More

785 views 1 answer







A machine's output is 4000 joules and its frictional losses are 1000 joules. Which of the following is its efficiency? Is it: w) 25% x) 30% y) 75% z) 80%
Last Answer : ANSWER: Z -- 80%

Show More

15 views 1 answer







127 views 0 answers







Hysteresis losses in electrical machines is equal to a. B1.2max f b. B1.6max f c. B1.2min f d. B1.2max fmin 
Last Answer : Hysteresis losses in electrical machines is equal to a. B1.2max f b. B1.6max f c. B1.2min f d. B1.2max fmin 

Show More

62 views 1 answer







In electronic fuel injection, there is improvement in the _____________ efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses. a) mechanical b) volumetric c) overall d) none of the mentioned
Last Answer : Answer: b Explanation: In electronic fuel injection, there is improvement only in the volumetric efficiency due to comparatively less resistance in the intake manifolds which will cause less pressure losses and no other efficiencies are hindered.

Show More

0 views 1 answer







The mechanical splice is best suited for ∙ A. quicker installation under ideal condition ∙ B. minimum attenuation losses ∙ C. field service conditions ∙ D. situations in which cost of equipment is not a factor
Last Answer : D. situations in which cost of equipment is not a factor

Show More

3 views 1 answer







Total mechanical losses ( frictional losses , pumping loss in intake and exhaust and power accessories) will amount to a.10-20 % ihp b.2-10 % ihp c.20-30 % ihp d.30 -50 % ihp
Last Answer : a.10-20 % ihp

Show More

2 views 1 answer






Show More⇦ PreviousNext ⇨