Joule's law of Heating & Joules First Law

Edited By Vishal kumar | Updated on Sep 24, 2024 12:31 PM IST

What is Joules Law of Heating?

Joules as the electric current flows through the circuit, it increases the internal power of the conductor, resulting in the collision of electrons with the conductor atoms, which in turn leads to heat production. To measure the amount of heat generated as a result of this collision, Joule, an English scientist, proposed Joules law.

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Joule's law of Heating & Joules First Law

Joules law, when electrical energy passes through a conductor, produces heat H, which is directly proportional to the R's resistance of the conductor, the time at which the current flows, and the square of the magnitude of the current period I. Mathematically represented as H ∝ I² .Rt.

Also read -

Define Joule’s Law of Heating.

Joules law is mathematically represented by the following Equation

The temperature generated in the conductor due to the flow of electricity has always varied directly as the square of the current size where the resistance provided by the conductor and the flow time of the electric current do not change.

H ∝ i²

namely H ∝ i² When R and t are constant

The amount of heat generated by the conductor due to the flow of electrical energy is directly proportional to the resistance provided by the conductor when the flow time and current magnitude are constant.

namely H ∝ R When i and t are constant

The heat generated in the conductor due to the current flow is directly proportional to the current flow time when the electrical resistance and current magnitude do not fluctuate.

namely H ∝ t When i and t are constant

When these three conditions are combined, the standard formula that appears is provided by

Also read :

H ∝ i².R.tWheni, R and t all are variable

H = 1J

.i².R.t ∵J is a Joule constant

Its SI unit is Joule, i is the current flowing in the conductor, t current flow tim

Joule's law of heating

Joule's law is a mathematical interpretation of a scale in which resistance to a circuit converts electrical energy into thermal energy.

English naturalist James Prescott found that the amount of heat per second rising in the current conductor equals the electrical resistance of the fence and the current square.

The heat generated due to the current flowing in the electric wire is described in Joules. The statistical meaning of Joule's law is described below.

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Joules first rule

The first rule of thumb shows the relationship between the heat generated by the flow of electrical energy by the conductor.

Q = I²RT

Where,

Q indicates the temperature value

I show electricity

R the amount of electrical resistance on the conductor

T means time

NCERT Physics Notes:

Solved Example

Q1) Calculate the thermal energy produced to withstand 5 Ω when the current 3 flows through it for 2 minutes.

The temperature generated by the operator is given in the formula:

Q = I²RT

Substituting the values in the above figure we find

Q = 32 × 5 × 2 × 60 = 5400 J

Q2) The 300 Ω resistance heater is connected to the main feed for 30 minutes. If 10 current flows through a heater then what is the heat generated in the heater?

The temperature generated by the heater is calculated as follows:

Q = I²RT

to enter the values in the equation, we find

Q = 10²× 300 × 30 × 60 = 54000000 J or 54 MJ.

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Frequently Asked Questions (FAQs)

1. What Is the Joule heating effects of Joules Heating Caused by Electric Current?

When electrical energy passes through the conductor, it increases the internal energy of the system, which in turn increases the energy of the atomic net and its molecules, which in turn leads to heat production. The heat generated in the system mainly depends on the major factors, namely

Electrical resistance provided by the operator is more resistance; there will be more heat to be produced.

The more current it flows, the more time it has, the more heat it produces.

The current value exceeds the driver. The higher the current size; heat is highly generated.

2. What are some other uses of Joules law?

1. Electric Heating Device

Other electrical appliances such as an electric heater, an electric toaster, and an electric heater are based on the current energy efficiency policy. In these applications, Nichrome (nickel alloy and chromium) is used as a heating element in many electrical devices. This is for the following reasons,

Nichrome has some high opposition.

Nichrome has a very melting point.

Nichrome is not easily integrated.

2. Fuse cable

Fuse cord is a mixture that contains 37% lead and 63% tin. Fuse cable is always connected to the series in the electrical circuit. With its high resistance to low melting point, when a large amount of electrical energy flows through the electrical circuit, the fuse wire melts, thus making the circuit open and preventing any damage to electrical equipment.

3. Electric Lamp

The power cord provides very high resistance to electrical flow, which is why a high temperature is produced. This cord, when intensified by incandescence, emits light. The most used cable is Tungsten, which has a high melting point of 3380 ° C.

Electric arc and electric heating are also based on the joule heating effect of current electric heating.

Joules law of electric heating does not help even when the concept is used in systems such as transformers and dynamos. These are devices that help reduce energy loss due to the heat joule heating effect of electrical energy.

Other energy heating applications are:

Water heater

Incandescent lamp (when its cord is heated produces light).

Fuse (fuse melts and stops the flow of comments now in the region, reducing damage to home devices)

Electrical metal

Electric stove.

Thermistors: Thermistors are a type of resistance to their resistance when changes occur.

3. What About Joule vs. Watt?

Joule is a power unit of SI; it represents the amount of energy contained in the body. Watt is a measure of power conversion and is a unit of power SI.

Power = Time Power Time

Here unit Joule is equal to the value of a watt unit per second unit.

Watts = Joules / time

Energy is a measure of energy consumption per system.

1 Joule per second = 1 Watt

4. What is the significance of the Joule Act?

Joules law of temperature states that if the 'i' current passes through the resistor 'r' and the time 't' then the heat generated on the conductor is equal to the product of the square, the resistance at the same time.

5. What can Joules law predict?

Joules law, on electricity, is a mathematical definition of the rate at which circuit resistance converts electrical energy into thermal energy. ... You have found that the heat from a second equals the amount of electricity absorbed, or the loss of energy.

6. What is Joules law for burning section 10?

Joules law of temperature states that if the 'i' current passes through the resistor 'r' and time 't' then the heat generated in the conductor is equal to the product of the square square, the time resistance. H = i 2 rt.

7. Who got the Joule?

James Prescott Joule

James Prescott Joule, (born December 24, 1818, at Salford, Lancashire [now Greater Manchester], England - died October 11, 1889, Sale, Cheshire), an English scientist who discovered that different forces - mechanical, electrical, and thermal - alike is the same and can be changed to something else.