Heating effect of electric current, Physics, Electricity
Made by- Group 4
Group name- H.R Hertz
Group leader- Pragyan
Group members- 1. Aditya
• Electricity is the most widely used form of energy we
cannot see electricity, but we can see its effects. The
Electricity can produce different types of effects.
Basically the effect of electricity is conversion of
Electrical energy into other form of energy, such as
Light, Heat etc.
• When electric current flows in a circuit, it produces
various effects such as
• Heating Effect
• Luminous Effect
• Chemical Effect
• Magnetic Effect
• Out of the above four effects Heating effect and
magnetic effect are predominant. The heating effect of
electricity is one of common and unique effect.our text
• When a potential difference or Voltage is applied across
the ends of a conductive metallic wire, the free electrons
begin forced to move. When the electrons move the
electrons collide with the atoms. In these collisions, energy
of the electrons is transferred to the atom and the atoms
begin to vibrate more violently.
• As a result of this collusion heat is produced. Greater the
number of electrons flowing per second, greater will be the
rate of collisions and hence more heat is produced.
• This effect of electricity is called the “Heating Effect” of
electricity. The amount of heat produced by electrical
device in unit time depends on the :-
I. Resistance offered by the electrical device (circuit) and
II. Amount of current flowing through the electrical device
III. The time (duration) of electric current flow.
• In studies James Prescott Joule found that the heat
produced by a heating element is directly proportional
to the square of the electric current (I) passing
through the conductor,
• H α I2 (Current)
• And directly proportional to the resistance (R) of the
• H α R (Resistance)
• time (t) for which current passes through the
• H α t (Time)
• Joule’s concluded that the quantity of heat developed
in a current carrying conductor is equal to the product
of the square of the electric current, the resistance of
the conductor and the time of flow of current through
the conductor. If I is the current in ampere (A), R the
resistance of the conductor in ohm (Ω), t the time in
seconds (s) then the heat H produced in joule (J), is
• H = I2Rt
• If we pass a current through a high resistive load
higher amount of heat energy can produced by
conversion of electric energy. This effect to electric
current is used in many electrical appliances.
• The heating effect of electric current is utilized in
many electrical heating appliances such as Electric
Iron, Room Heater, Water Heater (Immersion Rod),
Heater etc. All these appliances contain high resistance
coils. These high resistance heating coils are made up
of nichrome, an alloy of nickel, chromium, manganese
and iron. The reasons for using nichrome as a heating
I. High melting point
II. High resistance
III. The coil can remain in red-hot condition for a long
• When the appliances are connected with Electric
Supply then a large amount of heat is produced in the
heating coils because of high resistance of connected
of nichrome wire.
• We see a thick metallic wire in the
bulb. It is made of tungsten metal.
In a glass vessel or bulb the
tungsten wire is kept sealed. The
glass bulb is filled with neutral gas
or vacuum. Neutral gases are
using now a days commonly. The
tungsten wire is known as filament
when the current flows through the
tungsten wire or filament it
becomes heated and emit light.
Due to the flow of current heating
• The conversion of electrical
energy into heat energy is used in
• The simple electric iron uses an
element made of Nichrome strip
insulated by mica. When the
current flows through the
nichrome stripped wire, a heat
produces and this heat makes the
bottom of electric iron hotter. This
heat is used for ironing of cloths.
• The conversion of electric energy into
heat is achieved by a process called
electric heating. Electric heaters are
used for this conversion process.
Electric heating finds many applications
in industrial as well as in cooking
processes. For example if we consider
electric heaters, its working is very
simple. It consists of an electrical
resistor in it.
• The electric heater works on the
principles of Joule’s law of heating.
According to this principle, when electric
current is passed through the resistor,
then the conversion of electric energy
into heat energy takes place.
• In different types of electrical
instruments fuses are used in
our houses. In any electric
circuit, in electric line, if there is
a sudden high rise of current,
then those instruments can be
burnt down or there can be fire.
The reason for this sudden high
rise of current is the short circuit
between two terminals of the
electrical line. A low melting
point conducting wire is
connected in series to avoid this
type of accident.
• According to Joule’s law how can we find the heating effect
of electric current?
• H = I2Rt H = VI t
• Which metal is used to make the filament of a light bulb?
• What is used as an element to heat the electric iron?
• Nichrome coated with mica
• What are the reasons for using nichrome wire as a heating
I. High melting point
II. High resistance
III. The coil can remain in red-hot condition for a long time.