This document discusses electric current and its effects. It begins by introducing electric charge and how it is measured. It then discusses electric current, including the difference between conventional and electron flow. It describes the components of an electric circuit including resistors and how various factors affect resistance. It explains the heating effect of electric current and some applications. It also covers electromagnets, how they are created, and their advantages over permanent magnets. Examples of uses for electromagnets in various devices and applications are provided.

1. ELECTRIC
CURRENT
ANDITS
EFFECTS
BY: MD OBAIDULLAH ANSARI

2. INTRODUCTION TO
CHARGE

4. HOW IS ELECTRIC CHARGE
MEASURED?

5. PROPERTIES OF
ELECTRIC CHARGE

6. Charge is transferred from the object to the object until the charge
is equally distributed over the whole system

8. ELECTRIC
CURRENT/ELECTRICITY
(I):

9. CONVENTIONAL CURRENT FLOW VS
ELECTRON FLOW

10. ELECTRIC CIRCUIT COMPONENTS
WITH SYMBOLS

15. CIRCUIT
DIAGRAM

16. ELECTRICAL
CIRCUIT

17. CLOSED
CIRCUIT/COMPLETE
CIRCUIT

18. OPEN
CIRCUITS

19. RESISTAN
CE:

20. FACTORS AFFECTING
ELECTRICAL RESISTANCE

22. EFFECT OF
ELECTRIC CURRENT

23. HEATING EFFECT OF
ELECTRIC CURRENT

24. THE AMOUNT OF HEAT GENERATED DEPENDS ON
FOLLOWING FACTORS

25. APPLICATIONS OF HEATING EFFECT
OF CURRENT

30. MINIATURE CIRCUIT
BREAKER (MCB)

32. Causes of Excess flow of current
Large current can flow in the household circuit under two
condition:
Short-circuit
Overloading

33. Short-circuit
Electric wires and cables consist of three wires:-
Live wires
Neutral wires
Earth wire

34. Whenever, the live wire and neutral wire touch each other in a circuit due to
defect or damage in wire, resistance of the circuit become zero and large
amount of current is flowing through the circuit.
“ A sudden flow of very large current due to direct contact of a
live and a neutral wire is called Short-circuit.”
Overloading:
When large no of electrical appliances are connected to a single
socket, they draw extremely large current from the house household
circuit. Wiring gets over-heated due to large current.
“The over-heating of electrical wiring in any circuit due to the
flow of large current through it is called Overloading.”

36. Magnetic Effect of Electric Current
When electric current flows through a current carrying conductor, it produces a
magnetic field around it. This can be seen with the help of a magnetic needle
which shows deflection.
The more the current, the higher the deflection.
If the direction of current is reversed, the direction of deflection is also reversed.

37. The direction of the magnetic field in electric current through a straight
conductor can be represented by using Right-Hand Thumb Rule.

38. Solenoid
A solenoid is a coil of wire that acts as a magnet while carrying an electric current.
It is a cylindrical coil wound into a tightly packed helix
Magnetic field produce by current carrying solenoid depends on no of turn.
If no of turns is more, stronger magnetic field is produce

39. Electromagnet
When we insert a soft iron rod inside the solenoid, it become a electromagnet.
Combination of coil and soft iron rod create a stronger magnet than the coil alone
An electromagnet produces a magnetic field on the passage of electric current
through a conductor. This field disappears when the current is turned off.

40. “An electromagnet is an artificial magnet which produces a magnetic field on
the passage of electric current through a coil of insulated wire wounded around
a soft iron rod is called Electromagnet.”
The strength of electromagnet can be increased by:
Increasing the no of turn in the coil
Increasing the current passing through the coil
Nature of the core material. Soft iron core produces
very strong electromagnet.

41. Advantages of Electromagnets over permanent Magnets
Magnetism of an electromagnet can be switch ON or OFF as per our requirement.
This is not possible with a permanent magnet.
An electromagnet can be made very strong by increasing the no of turn and
amount of current. But a permanent magnets are not so strong.

43. Uses of Electromagnets
Uses in Home Appliances: Most of the electric appliances used in the home use
electromagnetism as the basic working principle. E.g. electric fan, motor, speaker,
electric doorbell, induction cooker, magnetic locks, etc.
Uses in Medical Field: The uses of electromagnets are also seen in the medical field.
MRI scan (Magnetic Resonance Imaging) is a device that uses electromagnets.
The device can scan all the tiny details in the human body with the help of
electromagnetism.
Uses in Memory Storage Devices and Computer Hardware: The data in eBook
gadgets and phones are stored in the electromagnetic format in the form of bytes
and bits. The computer hardware is also having a magnetic tape which works on
the principle of electromagnetism. Even in the olden days’ electromagnets had a
huge role in the data storage of audio and video tape-recorder.
Uses in Communication Devices and Power Circuits:
For separating magnetic substance from non-magnetic substances:
For lifting heavy load:
For removing iron particles from the eyes:

44. Electric bell
An electric bell consists of an electromagnet. The switch we press is used to make
the circuit complete.
The working of the bell is illustrated below When the switch (K) is pressed, current
flows through the circuit
The electromagnet (E) is powered and generates a magnetic field that attracts
the iron strip towards it
The striker strikes the gong or bell (B).
When the striking arm (A) strikes the gong, the contact at (T) is broken and current
stops flowing through the circuit
This causes the electromagnet to lose its magnetic field
The connected spring arm returns the striker to its original rest position
The contact is restored and current flows through the circuit (provided the main
switch is still pressed)
The process is repeated again until the switch (K) is made open