The trunk (North American English) or boot (British English) of a car is the vehicle’s main storage or cargo compartment, often a hatch at the rear of the vehicle. It is also called a tailgate.
Why the resistance of armature of a DC machine is low?
The armature produces a back EMF depending on its speed, which bucks the supply voltage. The armature current then will depend on the difference between the supply voltage and the EMF. So the armature resistance must be low enough to allow sufficient current to flow even with this reduced voltage.
What is the armature resistance of DC motor?
A DC electric motor spinning at 4500 RPM draws 3 amps of current with 110 volts measured at its terminals. The resistance of the armature windings, measured with an ohmmeter when the motor is at rest, unpowered, is 2.45 ohms.
What is the normal value of the armature resistance of a dc motor?
Answer : The normal value of the armature resistance of a d.c. motor is 0.5.
Which is winding have very low resistance for DC motor?
Resistance of series winding is less. It carries more current since directly connected in series with the armature. Speed is not constant.
How is armature resistance measured in a dc motor?
A practical way to measure the winding resistance is to use the Ohm’s law: Resistance = Voltage / Current. If you apply a power source to the windings and measure the voltage and current flowing through them, a simple division will yield an accurate value for the resistance.
How do I get armature resistance?
The Armature Resistance Of Series DC Motor Using Voltage formula is defined as the resistance of the armature winding of the series dc motor and is represented as Ra = ((V-Ea)/Ia)-Rse or armature_resistance = ((Voltage-Induced Voltage)/Armature Current)-Series field resistance.
What is the speed of DC motor?
DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.
What is a DC series motor?
Series DC motors are a group of self-excited DC motors in which the field coil is connected in series to the armature winding and thus a higher current passes through it. A series DC motor mission is to turn the electrical energy into mechanical one based on electromagnetic law.
What is the efficiency of DC motor?
The value of the efficiency of a DC motor could typically be in the range of 70 to 85%. Larger the machine higher will be the efficiency. Losses consist of Armature and field copper losses, core loss, friction and windage loss.
How do you find the speed of a DC motor?
conductors in armature. Hence, speed of a DC motor is directly proportional to emf of rotation (E) and inversely proportional to flux per pole (φ). N=120f/P.