I believe it has to do with the windings in the motor. When wired to 120V, half the motor has a positive polarity and the other half has a negative polarity. Then as the current alternates (60 hertz AC) the polarity flips, the magnetic poles oppose each other and cause the motor to spin. I think in a 240v winding the motor is in quadrants instead of halves. So it would be like have 4 magnets opposing each other instead of two and you have double the voltage. The calculation for electrical power (which is converted to torque) is voltage-squared divided by the resistance. If the voltage is doubled, the power is increase by 2-squared, or quadrupled. In reality, the torque produced will be slightly less than 4 times more (because some of the power is lost as heat), but it should be pretty close. -- The second answer is the best answer. The first answer could suggest several things, depending on how you read it. Nonetheless, they are all incorrect. The power calculation (in Watts) is really all you need to do. Voltage squared, divided by resistance. Resistance stays the same, so power quadruples when voltage doubles. If the motor spins at the same speed, then torque should effectively be linear with power, aside from the extra heat created in the components from the higher current.
The effect of a torque is to produce angular acceleration and that of the force is to produce linear acceleration. Since the effects of both torque and force are entirely different, therefore, a torque cannot be balanced by a single force.
electric motors produce torque so in the sense yes
A torque acting on an object tends to produce rotation.
ac voltage
It doesn't. A 3-phase motor will provides constant torque because the three alternating fields produce exactly the same effect as a single rotating field.
Current is directly proportional to applied voltage. Ohm's law.
at the time of starting when syncchronous torque is zero , i.e. when the motor starts with the help of starting torque , the armature current required to produce sync. torque is zero. If V = E(b) i.e. When back emf E(b) equals supply voltage.
Any time there is a force, there can be torque.
Types of MotorsThere are different types of Capacitor-start motors designed and used in various fields. They are as follows:Single-voltage, externally reversible type,Single-voltage, non-reversible type,Single-voltage reversible and with thermostat type,Single-voltage, non-reversible with magnetic switch type,Two-voltage, non-reversible type,Two-voltage, reversible type,Single-voltage, three-lead reversible type,Single-voltage, instantly-reversible type,Two speed type, andTwo-speed with two-capacitor type.These motors can be used for various purposes depending upon the need of the user. The starting, speed/torque characteristics of each of the above motors can be analyzed before employing them in work.
Torque is the product of (force) x (distance from the center of rotation).So with a distance from the center that's large enough or small enough,any force can produce as much or as little torque as you want.
power = torque * rpm
Torque