stance
u against a uniform electric field
will it travel before coming to momentary rest ?
48. A particle of mass 1 g and charge 2.5 x 10"C is released
from rest in an electric field of 1.2 x 10'NC. (a) Find
the electric force and the force of gravity acting on this
particle. Can one of these forces be neglected in comparison
with the other for approximate analysis ? (b) How long will
it take for the particle to travel a distance of 40 cm ? (c
)
What will be the speed of the particle after travelling this
distance ? (d) How much is the work done by the electric
force on the particle during this period ?
Answers
An electric motor is a device that converts electrical energy into mechanical energy.
Construction and working principle of an electric motor
Electric motors and their functions:
A power supply – In general, a simple motor has a DC power source. It provides power for the armature of the motor or field coils.
Field Magnet (can be a permanent magnet or an electromagnet) – The magnetic field by virtue of Fleming’s left-hand law, helps to produce a torque on the rotating armature coil.
An Armature or rotor – Maintains the position of the armature coil and provides mechanical support.
Commutator – It is the Armature Coil revolving interface with a stationary circuit.
Armature Coil – Supporting the engine to run.
Brushes – It is a system that conducts current between stationary wires and moving parts, mostly rotating shafts.
Axle
Working principle of electric motors:
The working of an electric motor is based on the assumption that a conductive current generates a magnetic field around it. Consider the following situation,
Take two bar magnets, and leave a small space between the poles facing each other. Now, take a small conductive wire length and make a loop. Keep this connection between the magnets, so that it is still inside the magnet’s area of influence. Now for the final part. Attach loop ends to battery terminals.
As electricity flows through your simple circuit, you will find that your loop moves. The magnet’s magnetic field interferes with that generated by the conductor’s electrical current flow. Because the loop has become a magnet, it will draw one side of it to the magnet’s north pole, and the other to the south pole. That causes the loop to rotate continuously. This is the idea of an electric motor working.