# What is resistor and its uses?

A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Resistors can also be used to provide a specific voltage for an active device such as a transistor.
A.

### What is a resistor and how does it work?

Devices called resistors let us introduce precisely controlled amounts of resistance into electrical circuits. Photo: Four typical resistors sitting side by side in an electronic circuit. A resistor works by converting electrical energy into heat, which is dissipated into the air.
• #### How do you read the value of a resistor?

Steps
1. Position the resistor with the gold or silver color band to the right..
2. Read the color sequence that must be decoded to determine resistance.
3. Determine the coded number for the resistive value.
4. Determine the tolerance of the resistor.
5. Determine the decoded number for the resistive value.
• #### Is a light bulb a type of resistor?

The reason a light bulb glows is that electricity is forced through tungsten, which is a resistor. The energy is released as light and heat. A conductor is the opposite of a resistor. Electricity travels easily and efficiently through a conductor, with almost no other energy released as it passes.
• #### What is a capacitor and what does it do?

A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. Unlike a resistor, a capacitor does not dissipate energy. Instead, a capacitor stores energy in the form of an electrostatic field between its plates.
B.

### What is the importance of a resistor?

The main function of resistors in a circuit is to control the flow of current to other components. Take an LED (light) for example. If too much current flows through an LED it is destroyed. So a resistor is used to limit the current.
• #### How do we measure resistance?

Electrical resistance is measured by either of two methods: constant current or constant voltage. The constant current technique sources a known current through an unknown resistance and the resulting voltage is measured. This technique is generally used for resistance values below 200M ohms.
• #### Why capacitors are used?

Power conditioning. Reservoir capacitors are used in power supplies where they smooth the output of a full or half wave rectifier. They can also be used in charge pump circuits as the energy storage element in the generation of higher voltages than the input voltage.
• #### What is a transistor and what does it do?

A transistor is a miniature electronic component that can do two different jobs. It can work either as an amplifier or a switch: Transistors can also work as switches. A tiny electric current flowing through one part of a transistor can make a much bigger current flow through another part of it.
C.

### Do resistors lower voltage?

In short: Resistors limit the flow of electrons, reducing current. Voltage comes about by the potential energy difference across the resistor. The mathematical answer is that a resistor is a two-terminal electric device which obeys, or you could say enforces, Ohm's law: V=IR.
• #### Can you use a resistor to reduce voltage?

The voltage dropped by a resistor is given by Ohm's Law: V = I R. So if you know exactly how much current your device will draw, you could choose a resistor to drop exactly 7.5 V, and leave 4.5 V for your device, when that current is run through it.
• #### What happens to current If you add resistors?

In a series circuit, adding more resistors increases total resistance and thus lowers current. But the opposite is true in a parallel circuit because adding more resistors in parallel creates more choices and lowers total resistance. If the same battery is connected to the resistors, current will increase.
• #### Is potential difference and voltage drop the same thing?

Voltage is the potential difference between the source & any point in the circuit. Voltage drop means, amount of voltage by which voltage across load resistor is less then the source voltage. Voltage across the resistor = Potential difference between the two terminal of the resistor, which here is V(load).

Updated: 3rd October 2019