As magnetic field of dc motor is constant. Whenever a current is given to rotor winding there will be a magnetic flux in air gap between rotor and winding so there will be torque in rotor of f=ibl.
so due to this torque rotor get rotate and get started.
usually ac 110v even on the dc motors
if you power an ac motor with dc or a dc motor with ac you will likely start smelling smoke and the motor will be damaged. If the motor is marked "3-phase", "shaded pole", or "induction" it is an ac motor! BTW, there are ac/dc motors that will run on both, they are wound very much like dc motors but a bit differently.
it maintains a constant speed under varing load
torque is not measured in mass units 20kg force = 20kg * 9.8meters/sec/sec or 20Newtons ive seen torque wrenches in kg-meters as well as newton-meters and foot-pounds a pound is 32.2 slug feet/sec/sec most power drills have dc motors if you get one with a large chuck 3/4" or so it will have 20kg meter or 400ft lb ( brand name holehog for example) older locomotives have dc motors on each axle usually about a 1-1 ratio gearing 300-500Hp for each motor newer locomotives can use ac motors with the advent of variable frequency ac drives - although it takes a bit more power to achieve the same starting torque
We Can find the Electric Motor in the vehicle as a self, which helps to start the engine initially.
because the dc motor will act as dc generator as same as dc generator acts as a dc motor .so it is called as dc machines.AnswerBecause generators and motors are machines, and operate on d.c.'A.C. machines' are generators, transformers, and motors which operate on a.c.
actually dc motors are of several types in which one of them are 1).brushed 2).brushless ...so the motor present in DVD are the brushless dc motors ...
DC motors can spin at a much faster speed and have higher starting torque.
Ac motor has a low starting torque so that DC series motor used in railways cause DC motor has high starting torque
usually ac 110v even on the dc motors
we can make it dc batteries &dc motors which is more effeicent in high starting torque.energy is saved by solar cells.
DC motors are not common in industry. However traction motors are one such main DC motor application. There are many tools, toys, drones, which use DC motors run by batteries.
only shunt dc motors have varaible speed control. compound dc motors do however NT as much, plus they are just a mixture of series and shunt dc motors.
Examples of DC electric motors are the starter in your car and the motor in a DC controlled elevator, to name just two.
Basically anything that works with batteries usually works with DC motors, i.g. your hard drive, your cellphone vibrator, toys, etc. Also, even for large motors, the DC motor has the advantage of being easily controlled by input voltage. Induction motors, on the other hand, can use controlled input voltage but they will have to deal wth low torque when the voltage is low. DC motors are used for those little fans in your computer. Also, CD players also use DC motors to spin the discs. DC motors are important where absolute speed control and feedback are necessary. For your household appliances, including fan motors, those are AC motors, cheaper for the industrial strength and more efficient.
DC motors are generally more efficient than AC motors. DC motors have a lower amount of inertial associated with them, making them more efficient to run.
Split Phase Induction Motor.