How do you increase the resistance of a resistor?

Increasing the temperature (typically) increases resistance. The temperature coefficient of resistance (TCR) of wire or a resistor relates the change in resistance to the change in temperature.

How do you reduce the resistance of a resistor?

In order to decrease/increase resistance (in that specific order): Replace resistors with lower/higher resistance ones. Remove/add resistors in series. Add/remove resistors in parallel.

Does rheostat increase or decrease current?

A rheostat is also known as a variable resistor where we can change the resistance of the circuit and its generally used for controlling the amount of current flowing in the circuit. So, a rheostat can increase as well as decrease the current. Hence, the correct option is C.

Does increasing current decrease resistance?

As the resistance increases, the current decreases, provided all other factors are kept constant. Materials with low resistance, metals for example, are called electrical conductors and allow electricity to flow easily.

What is the main reason why we need to increase decrease the rheostat?

By placing the rheostat in the electrical circuit, we can control (increase or decrease) the flow of electric current in the circuit. Rheostat reduces the electric current flow to certain level.

Why should rheostat have low resistance?

A rheostat is used to provide variable resistance in the circuit. As far as the internal resistance of the rheostat itself is considered, it should be low(if any). This is because the resistance of the rheostat should not interfere with the current flowing in the circuit which is undesirable.

What happens when you increase the resistance of the rheostat?

If we increase the resistance of the rheostat, the flow of electric current through the light bulb decreases. As a result, the light brightness decreases. In the similar way, if we decrease the resistance of the rheostat, the flow of electric current through the light bulb increases. As a result, the light brightness increases.

How can rheostat change the current without changing int voltage?

How can rheostat change the current without changing int voltage. And, as before, the voltage across the series combination of rheostat and bulb is fixed. Thus, as the resistance of the rheostat increases, the current through the bulb decreases. However, we can also say, with equal validity, that the rheostat controls the voltage across the bulb.

How does a rheostat change the intensity of light?

Rheostats are used in dim lights to change the intensity of light. If we increase the resistance of the rheostat, the flow of electric current through the light bulb decreases. As a result, the light brightness decreases.

What are the applications of rheostats in electrical circuits?

For example, for high current circuits, large rheostats are used. They are also used in dimmer circuits, Speed control circuits for motors, heaters and ovens. Since they dissipate heat, they have low efficiency and hence are now being replaced by pulse width controlled switching devices.