How heat energy is related to potential difference and resistance?

How heat energy is related to potential difference and resistance?

Joule’s Law of Heating: Let; an electric current I is flowing through a resistor having resistance equal to R. The potential difference through the resistor is equal to V. The charge Q flows through the circuit for the time t. Example 3: An electric heater having resistance equal to 5Ω is connected to electric source.

What is the relationship between resistance and time?

Resistance is directly proportional to the length. This means that any change in length of the material will change its value of resistance.

What is the relationship of resistance and current?

The relationship between current, voltage and resistance is expressed by Ohm’s Law. This states that the current flowing in a circuit is directly proportional to the applied voltage and inversely proportional to the resistance of the circuit, provided the temperature remains constant.

What is the relation between area and resistance?

The relationship between resistance and the area of the cross section of a wire is inversely proportional . When resistance is increased in a circuit , for example by adding more electrical components , the current decreases as a result.

Is power is directly proportional to resistance?

Here, we can see that the electric power is directly proportional to resistance on keeping I constant. When power increases, the resistance also increases, while keeping current I constant. However, when the resistance in the circuit decreases, power in the circuit also decreases, while keeping current I constant.

How does heat affect resistance?

When the metal is heated, the electrons absorb more energy and move faster. This leads to more scattering, thus increasing the amount of resistance. Thermometers actually use the change in electrical resistance in a piece of wire to measure temperature.

Does resistance increase with temperature?

Hence, for a metal, resistance increases with increasing temperature . Often the increase in temperature is caused by an increase in current. An example is a filament lamp. As current increases, the filament gets hotter and the resistance of the bulb increases.

How does temperature affect the resistance of a wire?

Resistance increases with the temperature of the wire. The hotter wire has a larger resistance because of increased vibration of the atomic lattice. When a material gets hotter the atoms in the lattice vibrate more. This makes it difficult for the electrons to move without interaction with an atom and increases resistance.

What is the formula for temperature coefficient of resistance?

The temperature coefficient of resistance is normally standardised in relation to a temperature of 20°C. This temperature is typically taken to be normal “room temperature.”. As a result the formula for the temperature coefficient of resistance normally takes this into account: R = R 20 ( 1 + α 20 ( T – 20 ) )