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Joule's laws are a pair of laws concerning the heat produced by a current and the energy dependence of an ideal gas to that of pressure, volume, and temperature, respectively. Joule's first law, also known as the Joule effect, is a physical law expressing the relationship between the heat generated by the current flowing through a conductor. It is named for James Prescott Joule who studied the phenomenon in the 1840s. It is expressed as: : Where Q is the heat generated by a constant current I flowing through a conductor of electrical resistance R, for a time t. When current, resistance and time are expressed in amperes, ohms, and seconds respectively, the unit of Q is the joule. Joule's first law is sometimes called the Joule-Lenz law since it was later independently discovered by Heinrich Lenz. The heating effect of conductors carrying currents is known as Joule heating. Joule's second law states that the internal energy of an ideal gas is independent of its volume and pressure, depending only on its temperature.
Joule's law states that the amount of heat produced by a current passing through a resistor is directly proportional to the square of the current and the resistance of the resistor, and is also proportional to the time the current flows. In equation form, it is expressed as Q = I^2Rt, where Q is the heat produced, I is the current, R is the resistance, and t is time.
There are two joule's laws. The first shows how much heat is generated by a current flowing through a conductor. The second states that a gas's internal energy does not change with volume or pressure, but with temperature.
joules law state that , the heat generated in the conductor by the flow of electric current is proportional to the square of electric current value, the resistance value of the conductor & time taken to the flow of current.
Joule's Law describes the heat produced by a resistor in terms of the resistance and the current:
P = I2R
where P is the rate of heat production in watts, I is the current through the resistor in amperes, and R is the resistance of the resistor in ohms.
Alternate representations make use of Ohm's Law (V=IR):
P = VI = V2/R
where V is the voltage across the resistor.
The total heat energy produced by a resistor is found by integrating the equation with respect to time. For a constant current and resistance this is simply:
Q = I2Rt = VIt = V2t/R
where Q is the energy in Joules, and t is the time duration in seconds.
For example: A toaster has a 10-ohm resistance, connected to 120 volts. By Ohm's Law, it will draw a current of 12 amperes. By Joule's Law, it will emit heat at a rate of 1440 watts. If left on for 60 seconds it will produce 86,400 joules of heat energy. (Note that in a real toaster, the resistance of the heating element is not constant; it varies widely with the temperature).
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What law did James prescott joule came of?
James Prescott Joule is best known for his work in the field of physics and thermodynamics. He is responsible for the scientific law of the "Joule's Law," which states that the heat produced by a current in a conductor is proportional to the square of the current. This law helped to establish the relationship between electrical energy and heat.
Which scientist shared in discovering the law of conservation of energy and also developed a unit of energy?
James Prescott Joule is the scientist who shared in discovering the law of conservation of energy and he also developed the unit of energy known as the joule.
How do you derive joule's law?
Joule's law, which states the relationship between electrical power, current, and resistance, is derived from Ohm's law, P = IV, and the formula for electrical power, P = I^2R. By substituting I = V/R from Ohm's law into the power formula, you can derive Joule's law as P = V^2/R.
What is James joule famous for?
James Joule is famous for his work in the field of physics, particularly for establishing the relationship between heat and mechanical work. He formulated the law of conservation of energy and the first law of thermodynamics, which are fundamental principles in our understanding of energy. Joule also developed the concept of the mechanical equivalent of heat, which quantitatively relates mechanical work to heat energy.
What invention is James Prescott Joule most famous for?
James Prescott Joule is most famous for his work in the field of thermodynamics, particularly for discovering the relationship between mechanical work and the generation of heat. This led to the formulation of the first law of thermodynamics, also known as the law of conservation of energy.
What law did James prescott joule came of?
James Prescott Joule is best known for his work in the field of physics and thermodynamics. He is responsible for the scientific law of the "Joule's Law," which states that the heat produced by a current in a conductor is proportional to the square of the current. This law helped to establish the relationship between electrical energy and heat.
Which scientist shared in discovering the law of conservation of energy and also developed a unit of energy?
James Prescott Joule is the scientist who shared in discovering the law of conservation of energy and he also developed the unit of energy known as the joule.
How do you derive joule's law?
Joule's law, which states the relationship between electrical power, current, and resistance, is derived from Ohm's law, P = IV, and the formula for electrical power, P = I^2R. By substituting I = V/R from Ohm's law into the power formula, you can derive Joule's law as P = V^2/R.
What is James joule famous for?
James Joule is famous for his work in the field of physics, particularly for establishing the relationship between heat and mechanical work. He formulated the law of conservation of energy and the first law of thermodynamics, which are fundamental principles in our understanding of energy. Joule also developed the concept of the mechanical equivalent of heat, which quantitatively relates mechanical work to heat energy.
What law expresses the relationship between the current in a resistor and the rate at which it produces heat?
.Faraday's Law Joule's Law Lenz's Law Ohm's Law
What invention is James Prescott Joule most famous for?
James Prescott Joule is most famous for his work in the field of thermodynamics, particularly for discovering the relationship between mechanical work and the generation of heat. This led to the formulation of the first law of thermodynamics, also known as the law of conservation of energy.
What law did James joule prove?
that we should all have the opportunity to attend a university
How did the work of James Joule impact science?
James Joule was a 19th century mathematician and physicist, and his investigations of what heat is and how it works paved the way to the law of the conservation of the conservation of energy, and a bit later on to the first law of thermodynamics.
How can joule law be demonstrated experimentally?
Joule's law can be demonstrated experimentally by using a setup where electrical energy is converted into heat energy as current flows through a resistor. By measuring the voltage across the resistor and the current passing through it, the power dissipated as heat (P = I^2 * R) can be calculated. The increase in temperature of the resistor due to the heat generated confirms Joule's law.
Who was James joule by profession?
James Joule was a British physicist who is known for his work in thermodynamics. He established the principle of conservation of energy and formulated Joule's law, which quantifies the relationship between heat produced and current flowing through a resistor.
What evidence is there that Joule had an exceptional?
James Prescott Joule, a 19th-century physicist, had an exceptional reputation for his work in the field of thermodynamics. His most notable contribution is the discovery of the first law of thermodynamics, also known as the law of conservation of energy. Additionally, Joule's experiments on the relationship between mechanical work and heat laid the foundation for the science of thermodynamics.
What did James joule do?
James Prescott Joule (December 24, 1818- October 11, 1889) established that the various forms of energy are basically the same and can be changed into one another. His ideas formed the basis for the first law of thermodynamics, the conservation of energy.
