## What happens when you put a resistor in a circuit?

Limiting current: By introducing resistance into a circuit, resistors can limit the amount of current that flows through the circuit. In accordance with Ohm’s law, if the voltage in a circuit remains the same, the current will decrease if you increase the resistance.

## What is P in the formula P IE?

Ohm’s law equation (formula): V = I × R and the power law equation (formula): P = I × V. P = power, I or J = Latin: influare, international ampere, or intensity and R = resistance. V = voltage, electric potential difference Δ V or E = electromotive force (emf = voltage).

## What is J in Ohm’s law?

Microscopically, Ohm’s law is a statement about how application of an electric field to a conducting material leads to an electric current: J ⃗ = σ E ⃗ . In the above equation, σ is a constant called the conductivity of a material, E is the applied electric field, and J is the electric current density at a point.

## What is unit of resistivity?

Resistivity, commonly symbolized by the Greek letter rho, ρ, is quantitatively equal to the resistance R of a specimen such as a wire, multiplied by its cross-sectional area A, and divided by its length l; ρ = RA/l. Thus, in the metre-kilogram-second system, the unit of resistivity is ohm-metre.

## What is resistivity derive its formula?

Resistivity is the resistance per unit length and cross-sectional area. We know that R = ρ L / A. Thus we can derive the expression for resistivity from this formula. ρ = R A / L, where R is the resistance in ohms, A is the area of cross-section in square meters and L is the length in meters.

## Why is heat directly proportional to resistance?

Solution : (i) Heat produced in the circuit is directly proprotional to the resistance if a constant current is flowing through a circuit, because H=I2RtorH∝R. It is so in series combination of resistors. It is so in parallel combination of resistors.

## Is resistance directly proportional to power?

Power in electronics is the rate of doing work. Resistance is the opposition offered against the flow of electrons. The relation between power and resistance is proportional.

## Does Resistance increase power?

The power dissipated in a resistor is given by P = V2/R which means power decreases if resistance increases. Yet this power is also given by P = I2R, which means power increases if resistance increases.