AC AND DC ELECTRICITY
UNIT 15
, ALTERNATING CURRENT(AC) AND DIRECT CURRENT(DC)
An alternating current is an electrical current which periodically
reverses direction whereas a direct current flow in one direction.
Direct current is produced by cells and batteries whereas an
alternating current is produced by a generator. AC is mainly used in
electronic circuits such as computers and mobile phones while DC is
mainly used in electricity which is used in the homes.
AC electricity generator consists of a coil of wire rotating in a magnetic
field. To generate an AC electricity the coil is rotated in the magnetic field during the rotating coil the current is
induced where the sling rings get connected to the coil and the brushes make continuous contact between the
external circuit and the sling rings which contributes to the flow of current in the external circuit. The
maximum current can be achieved by increasing the rate of rotation, increasing the strength of the magnetic
field and increasing the number of turns on the coil.
This diagram shows different positions of the coil and the
corresponding potential difference produced.
Voltage varies according to coil position, when the coil is
horizontal and moving at 900 to the direction of the magnetic
field the maximum voltage is induced whereas when the coil
is half turned, parallel or moving in 1800 to the direction of
the magnetic field the voltage is not induced.
FLEMING’S RIGHT HAND RULE
FLEMING’S RIGHT HAND RULE
Fleming's right-hand rule is applicable for electric generators, due to Faraday's law of
electromagnetic induction, this rule is to find out the direction of induced current in a conductor which is
moving perpendicular to the magnetic field. Whenever a conductor is forcefully moved in an electromagnetic
field, an emf gets induced across the conductor. Hold the thumb and first two fingers of the right hand at right
angles. And If point correctly as shown the second finger will indicate which way the current is flowing. (Admin
E4US, 2020)
FLEMING’S LEFT HAND RULE
Fleming’s left hand rule it state “if we hold the thumb, fore finger and middle finger
of the left hand perpendicular to each other such that the fore finger in the direction
of the magnetic field, the middle finger points in the direction of magnetic field, the
middle finger points in the direction of current, then the thumb shows the direction
of the force(motion) of the conductor” this means it is possible to predict the
direction of the force acting on a wire, its motion, and its direction of current or the
magnetic field are known. (Electrical4U, 2012)
UNIT 15
, ALTERNATING CURRENT(AC) AND DIRECT CURRENT(DC)
An alternating current is an electrical current which periodically
reverses direction whereas a direct current flow in one direction.
Direct current is produced by cells and batteries whereas an
alternating current is produced by a generator. AC is mainly used in
electronic circuits such as computers and mobile phones while DC is
mainly used in electricity which is used in the homes.
AC electricity generator consists of a coil of wire rotating in a magnetic
field. To generate an AC electricity the coil is rotated in the magnetic field during the rotating coil the current is
induced where the sling rings get connected to the coil and the brushes make continuous contact between the
external circuit and the sling rings which contributes to the flow of current in the external circuit. The
maximum current can be achieved by increasing the rate of rotation, increasing the strength of the magnetic
field and increasing the number of turns on the coil.
This diagram shows different positions of the coil and the
corresponding potential difference produced.
Voltage varies according to coil position, when the coil is
horizontal and moving at 900 to the direction of the magnetic
field the maximum voltage is induced whereas when the coil
is half turned, parallel or moving in 1800 to the direction of
the magnetic field the voltage is not induced.
FLEMING’S RIGHT HAND RULE
FLEMING’S RIGHT HAND RULE
Fleming's right-hand rule is applicable for electric generators, due to Faraday's law of
electromagnetic induction, this rule is to find out the direction of induced current in a conductor which is
moving perpendicular to the magnetic field. Whenever a conductor is forcefully moved in an electromagnetic
field, an emf gets induced across the conductor. Hold the thumb and first two fingers of the right hand at right
angles. And If point correctly as shown the second finger will indicate which way the current is flowing. (Admin
E4US, 2020)
FLEMING’S LEFT HAND RULE
Fleming’s left hand rule it state “if we hold the thumb, fore finger and middle finger
of the left hand perpendicular to each other such that the fore finger in the direction
of the magnetic field, the middle finger points in the direction of magnetic field, the
middle finger points in the direction of current, then the thumb shows the direction
of the force(motion) of the conductor” this means it is possible to predict the
direction of the force acting on a wire, its motion, and its direction of current or the
magnetic field are known. (Electrical4U, 2012)
