In a d.c. motor, the mechanical output power actually comes from?

In a d.c. motor, the mechanical output power actually comes from?
by

1 Answer

Answer :

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

by

Related questions

The mechanical power developed by the armature of a d.c. motor is equal to?

Description : 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.

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

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.

The synchronous motor which works on leading power factor and does not drive any mechanical load is called?

Description : 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.

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

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

Last 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.

The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and

Description : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is (A) 0.25 pu (B) 0.5 pu (C) 1.0 pu (D) 1.5 pu

Last Answer : The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is 0.5 pu

The condition for maximum power in case of D.C. motor is?

Last Answer : (b) Clostridium butylicum Lipase Removal of oil stains

The power mentioned on the name plate of an electric motor indicates?

Last Answer : The power mentioned on the name plate of an electric motor indicates the output power available at the shaft.

In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be?

Last Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.

When a D.C. series motor is connected to A.C. supply, the power factor will be low because of?

Last Answer : When a D.C. series motor is connected to A.C. supply, the power factor will be low because of high inductance of field and armature circuits.

The power factor of a single-phase induction motor is usually?

Last Answer : The power factor of a single-phase induction motor is usually lagging.

The value of starting capacitor of a fractional horse power motor will be?

Last Answer : The value of starting capacitor of a fractional horse power motor will be 300 uF .

A synchronous motor has better power factor as compared to that of an equivalent induction motor...

Description : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because?

Last Answer : A synchronous motor has better power factor as compared to that of an equivalent induction motor. This is mainly because stator supply is not required to produce magnetic field.

An induction motor has relatively high power factor at?

Last Answer : An induction motor has relatively high power factor at near full load.

If the load of the normally excited synchronous motor is increased the power factor will?

Description : If the load of the normally excited synchronous motor is increased the power factor will?

Last Answer : If the load of the normally excited synchronous motor is increased the power factor will become lagging.

If the field of synchronous motor is under excited, power factor will be?

Description : If the field of synchronous motor is under excited, power factor will be?

Last Answer : If the field of synchronous motor is under excited, power factor will be lagging.

The synchronous motor will develop maximum power when the load angle is?

Description : The synchronous motor will develop maximum power when the load angle is?

Last Answer : The synchronous motor will develop maximum power when the load angle is 900.

Can we make power factor of synchronous motor leading by adjusting its excitation?

Last Answer : Yes, we can make the power factor of synchronous motor leading by adjusting its excitation.

At which time power factor of the induction motor is low?

Description : At which time power factor of the induction motor is low?

Last Answer : The power factor of the inducction motor is low at the time of starting as compare to while the induction motor is running.

Briefly explain how an electrical generator converts mechanical energy into electrical energy

Description : 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. 

Explain the suitability of aluminium as an electrical conductor with respect to its mechanical and electrical properties.

Description : 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. 

Define natural, mechanical, forced and induced draught systems.

Description : 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

Explain the mechanical properties of insulating materials.

Description : 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.

Which of the following converts linear displacement from a mechanical reference into a proportional

Description : 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

In Torque-Voltage analogy, the Moment of Inertia of a mechanical rotational system is analogous to

Description : 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.

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

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

As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for?

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

A d.c. motor can be looked upon as d.c. generator with the power flow?

Description : A d.c. motor can be looked upon as d.c. generator with the power flow?

Last Answer : A d.c. motor can be looked upon as d.c. generator with the power flow reversed.

Explain the necessity of starter for D.C. motor. State various types of D.C. motor starter.

Description : Explain the necessity of starter for D.C. motor. State various types of D.C. motor starter. 

Last Answer : Necessity of Starter for D.C. Motor: Armature current is given by equation Ia = (V−Eb)/Ra i) If the motor is at standstill or rest, back emf Eb is zero (as Eb= ZNP/(60A), at start speed N ... . Types of D.C. motor starters: i) Two point starter ii)Three point starter iii) Four point starter

State at least one function and the material used for the following parts of DC Motor.

Description : State at least one function and the material used for the following parts of DC Motor.

Last Answer : Part Function Material Yoke -Provides mechanical support for poles -Acts as protecting cover for machine -Provides path for magnetic flux Cast Iron OR Cast Steel Field Winding - ... Pole core  Provides mechanical support to field winding. Cast Iron OR Cast Steel

Why does the speed of a DC shunt motor decrease as the load increases?

Description : Why does the speed of a DC shunt motor decrease as the load increases?

Last Answer : Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.

The Eb/V ratio of a d.c. motor is an indication of its?

Description : The Eb/V ratio of a d.c. motor is an indication of its?

Last Answer : The Eb/V ratio of a d.c. motor is an indication of its efficiency.

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

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

Last Answer : The normal value of the armature resistance of a d.c. motor is 0.5.

The counter e.m.f. of a d.c. motor?

Description : The counter e.m.f. of a d.c. motor?

Last Answer : The counter e.m.f. of a d.c. motor helps in energy conversion.

In a d.c. motor, unidirectional torque is produced with the help of?

Description : In a d.c. motor, unidirectional torque is produced with the help of

Last Answer : Commutator provides unidirectional torque and pulsating dc

In DC motor iron losses are occurred in?

Description : In DC motor iron losses are occurred in?

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

Which D.C. motor has got maximum self relieving property ?

Last Answer : Series motor has got maximum self relieving property.

D.C. motor is to a drive a load which is almost nil for certain part of the load cycle...

Description : D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select the?

Last Answer : D.C. motor is to a drive a load which is almost nil for certain part of the load cycle and peak value for short duration. We will select the compound motor.

D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value...

Description : D.C. motor is to drive a load which has certain minimum value for most of the time and some peak value for short duration. We will select the?

Last Answer : DC motor mostly preferred is DC series motor becaus the load is continuous for a long time

If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens?

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.

When the armature of a D.C. motor rotates, e.m.f. induced is

Last Answer : When the armature of a D.C. motor rotates, e.m.f. induced is back e.m.f.

For which types of D.C. motor, dynamic braking is generally used ?

Last Answer : Shunt motors,  Series motors, Compound motors

In a manual shunt motor starter?

Last Answer : In a manual shunt motor starter over load relay is connected in series and no volt relay in parallel with the load.

Torque developed by a D.C. motor depends upon?

Last Answer : Torque developed by a D.C. motor depends upon magnetic field, active length of the conductor, current flow through the conductors, number of conductors, radius of armature.

Which motor should not be started on no-load ?

Last Answer : Series motor should not be started on no-load.

If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will?

Last Answer : If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will increase.

What is the difference between manual and automatic feed during turning

Description : Is not asked

Last Answer : In manual feed turning, the operator manually controls the feed rate of the cutting tool by turning a handwheel or other manual feed mechanism. This allows the operator to adjust the feed rate ... hand, is generally faster and more consistent, but it requires more complex equipment and programming.

Why does my computer (Mac OSX) grumble when it's working?

Description : 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.

What is the difference between basic hole and basic shaft ?

Description : 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.

What is the percentage of carbon in cast iron ?

Description : What is the percentage of carbon in cast iron ?

Last Answer : 2.5%.

A three-phase synchronous motor connected to ac mains is running at full load and unity power factor.

Description : A three-phase synchronous motor connected to ac mains is running at full load and unity power factor. lf its shaft load is reduced by half and field current is held constant then its new power factor will be

Last Answer : Leading