What is the purpose of a resistor in a circuit and how could it be used in a circuit?
Resistors are avoided if possible in power circuits because they waste energy and generate heat. One of the exceptions that comes to my mind would be the low-voltage start for motors in which resistors are temporarily inserted into the motor circuit when the motor starts, and then removed to operate.
Maybe heating elements of all types really work, so you can call anything that intentionally heats something that suits you, hobs, ovens, water heaters, home heating units, and so on.
Resistors can be a problem and an asset in an IC circuit. you can use resistors to amplify small signals or noise that makes circuits inefficient by dissipating more heat or energy. If you have a high parasitic rc constant, which is a time constant, you slow down the IC circuit. This question is somewhat general since the resistors can be used inside and outside of a liquid crystal chip. you may have resistors on a printed circuit board, for example, and the use of resistors on an electronic board has certain advantages. For example, you can reduce costs on the board rather than on the chip.
The resistors are components limiting the current. Their main purpose is to limit the flow of current in a circuit to avoid the damage that can be caused to the electronic components by the high current. this is done by absorbing the extra power.
A common example is a resistor with a led. a led must always be connected to a series resistor before connecting it to a power source, otherwise the LED could be damaged and sometimes even burst (depending on the amount of current flowing through it).
Resistors are used for many purposes. from the top of my head:
current limitation – pulling up / down 3v with a 1kohm resistor will ensure that there is only 3ma left in this wire.
voltage divider with feedback in the voltage regulation
feedback adjustment of an operational amplifier
going up in an open drain / collector connection.
0 Ohmic resistors are used as an option to connect or brake the
connection with current sensing – to convert the current into voltage for measurement.
polarization of circuits on certain fixed voltages by using a resistor chain as voltage divider
slow circuits by increasing the constant rc (the resistor reduces the current so that the capacitor is charged more slowly)
dacs: A long chain of resistors can create a variety of tensions.
blocking the alternating current (or the small signal): the big resistances allow the passage of the DC voltage while the small signals are dispersed.
However, as in any type of engineering, the resistors also have drawbacks such as heat, energy losses, etc., so that the compromises must be balanced.
basically, their function is to dispel the power. As long as the device is under voltage or under a current, it dissipates the current.
That being said, the dissipation of energy is a net cost and not a good thing; it becomes a use of energy over time. it is therefore important that the secondary functions are worth the energy cost of having them in the circuit.
the secondary functions that make the resistors useful are the following:
converts the voltage into current and voltage by ohm
control or limit the current flow
creates voltage drops when needed, for example dividers
voltage can then be associated with real applications that are of course too many to list.
The classic use is of course to help transform a galvanometer into a voltmeter.