Heating Effect of Electric Current by Fast2study

Heating Effect of Electric current:

When an electric current is passed through a conductor gets heated this phenomenon is known as the Heating Effect of Electric current.

Cause- Collides of electron and conductor atom.

JOULE,S LAW OF HEATING EFFECTS: 

The law which is given by joule scientist relation between heat and current is called Joule's law of heating effects. 

1st law:- According to this law heat produced by the conductor is directly proportional to the square of current when resistance and time are constant.

i.e.   H ∝ I²   ( R and t is constant ) --- (i)

2nd law:- According to this law heat produced by the conductor is directly proportional to resistance when current and time is constant.

i.e.    H ∝ R     ( I and t is constant ) --- (ii)

3rd law:- According to this law heat produces by the conductor is directly proportional to time when current and resistance is constant.

i.e.    H ∝ t      ( I and R is constant ) --- (iii)

from equation (i), (ii) and (iii)

H ∝ I²Rt 

H = K.I²Rt   when K=1

H = I²Rt 

H = IR x It

H = VIt  

  in the form of potential difference

H = IR x It

H = VQ  [Q=It]

 in the form of charge and potential difference

Heating Element:  Those type of appliance which heats up due to the heating effect of electric current is called the heating element.
example:-  Nichrome, Tungeston.
↪ It is made of materials of high resistance.

Also Read:

• Force on a Dielectric in a Capacitor.
• What is Coulomb’s Law and some related important point.
• Write the properties of Conductor.
• What is charge and also described properties of charge.

• Define and Explain Radioactive Element and Radioactivity

Electric Energy: The total work done by the current in an electric circuit is called electric energy.

↪ It is represented by 'E' .
↪ Its S.I unit is Joule.                                                                                            

↪ Its commercial unit is kilowatt-hour (Kwh).

↪ Its dimension is  [ML² T ^-2]

Suppose an Electric circuit in which 'I' current flow for time 't' during this time is charge 'Q' flows then,

           Q=It

If the potential difference between resistance is 'V' for the main  flow of charge then,

V = W/Q

VQ = W

W = Q x V

W = It x V

W = It.V = E

W = It x IR

W = E =  I²Rt  

W = I²Rt 

Electric energy = Electric power x time

E = P.t

Electric Power: The amount of electric energy consumed in a circuit per unit time is called electric power.

• It is denoted by ‘P’.
• It is a scalar quantity.
• Its dimension is  [ ML² T ^-3 ]
• Its S.I unit is Watt (W) or J/sec.

P = W/t = E/t = VI

P = W/t

P =I²Rt  /t

P =I²R

P = IR x I

P = VI

P = I²R

P = V²/R² x R

P =V²/R

One watt: If the one-joule work is done in one second by electricity then, the power of electricity is called one watt.

↪Its dimension is   [ ML² T ^-3 ]

Note:- Power has also unit Kilowatt, Megawatt, Gigawatt.

Some Largest Unit of Power:

1 Kilowatt = 10³ Watt

1 Megawatt = 10⁶ Watt

1 Gigawatt = 10⁹ Watt

1 Wh = 3600 J

Particle and experiment unit of power is horse-power (H.P)

1 H.P = 746 Watt

Commercial Unit of the Electrical Energy: The unit used to measure the electric energy in any traditional center is called the Commercial Unit of Electrical Energy.

• It is also known as Board of trade unit (B.O.T)
• In this unit energy measured in Kilowatt hour (kW-h)

1 unit = 1 kWh = 3.6 x 10⁶ J

One kilowatt-hour: The amount of electrical energy consumed by 1000 watt electrical appliance when it operates for one hour is called One kilowatt-hour.

          One kilowatt is also known as  “One unit”.

Relation between kilowatt-hour and Joule

1 Kwh = 1000 watt x h

1 kwh = 1000 J/sec x h

1 Kwh = 1000 j/sec x 3600 sec

1 Kwh = 3.6 x 10⁶ J

Power Rating of an Appliance: let, take a bulb if the bulb is lighted on a 220 V supply. It consumed 100 W electric power that means 100 J  of electric energy is converted in the filament of the bulb into heat energy and light energy in one second.

Efficiency of an Electric device: The ratio of output power to the input power is called the efficiency of an electric device.

      It is represented by ‘η’

η = output power/input power

Some Essential Components of the house wiring system

Electric Fuse: An electric fuse is a safety device that is used to limit the current in an electric circuit.

• It is a short length thin wire made of a tin-lead alloy having a low melting point.

• It is always connected in series in the wire of the circuit.

• It is provide overloading.

Switches: A switch is an on-off device for current in a circuit that is connected in the live wire.

Earthing (Grounding): Earthing is an appliance which means connecting the metal body buried deep in the earth through the earth-wire.

• It is used for safety measures.

Current Rating of Fuse: The maximum current that can flow through a fuse-wire is called the power or current rating of a fuse.

    The power of a fuse is 10 A, this means that the maximum the current of 10 A can flow through the fuse-wire.

Short Circuit:  When the live wire comes in direct contact with the neutral wire then heavy current passes through the appliance this is called short circuit.

Overloading: Overloading of the electric circuit means that the current circulating in the circuit becomes more than the capacity of components in the circuit to withstand the current.

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