# Chapter 7 – Ohm’s Law

The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

You might have experienced the flow of current in electronic current in your daily use equipment. Ever wondered how current flows in the electronic devices of different designs and sizes for this efficient working. One of the best explanations of this phenomenon is Ohm’s Law.

#### Ohm’s Law Explanation

Ohm’s law stated that the current flowing through some conductor is directly proportional to the potential resistance applied across the end of the circuit, provided if the temperature and other physical constraints remain unchanged throughout the process. Current in the circuit is also directly proportional with the voltage subjected to the difference passing through some resistor. Thus, if the current is double, the voltage gets double due to the direct relationship.

Ohm’s Law formula shows the direct relationship between voltage, resistance, and current is V = IR, where V is voltage, I is current, and R is resistance. For more information on this topic, visit the MSVgo application.

#### Experimental Verification of Ohm’s Law

For conducting an experimental Verification of Ohm’s Law, few materials are required, which are:

1. a resistor of 5 Ω,
2. an ammeter
3. a voltmeter,
4. four dry cells of 1.5 volts each with battery eliminator,
5. connecting wires, sandpaper, and a plug key.

For conducting a safe experiment, it is needed to ensure that all the connections with electricity are tight and safe and keep the voltmeter and ammeter at the proper range. Lastly, the plug key should only be inserted for taking reading to stay safe. The circuit diagram of the experiment is as follows: #### Ohm’s Law Magic Triangle

The key foundation of Ohm’s Law magic triangle is V= IR, which is the formula of Ohm’s law stated above. These three basic electrical units are presented in a triangle as follows: The units for measuring current (I), Voltage (V), and resistance (R) are ampere, volt, and Ohm, respectively. Using this triangle, key formulas of Ohm’s law are derived, which are:

1.     V=IR
2.     I=E/R
3.     R=E/I

#### Ohm’s Law Pie Chart

The pie chart of Ohm’s law is as follows: This pie chart helps develop a better understanding between the constraints of measuring electrical units with the addition of power as the fourth constraint and current, voltage, and resistance. For more information, browse the video library and material on the MSVgo application.

#### Ohm’s Law Matrix Table

Subjected to the Ohm’s Law pie chart, Ohm’s Law matrix table is developed, which is as follows:

 Known Values Resistance Current Voltage Power Current and Resistance – – V=I*R P= I*I*R Voltage and Current R=V/I -I – P=V*I Power and Current – – V=P/I – Voltage and Resistance – I=V/R – P= V*V/R Power and Resistance R= V*V/P I= √P/R V= √P*R – Voltage and Power I=P/V – –

This matrix shows that power within an electrical circuit is subjected to the presence of voltage and current. Thus, electrical power is a product of voltage multiplied by current, and the power dissipation in a circuit depends on the flow of voltage and current.

#### Ohm’s Law Applications

The key applications of Ohm’s Law are:

1. It helps in the determination of the voltage, resistance, and current in an electrical circuit.
2. It is used for maintaining voltage drop across varied electronic components as per the need.
3. It is used in DC ammeters, and other DC shunts to divert the current.

#### Limitations of Ohm’s

The key limitations of Ohm’s law are:

• This law does not apply to the unilateral electrical elements such as diodes and transistors due to the single direction flow of current
• It is difficult to use this law with respect to the non-linear electrical components with capacitance as voltage and current are not constant in them.

#### Calculating Electrical Power Using Ohm’s Law

• The rate at which the electrical energy is converted into mechanical energy, heat magnetic fields, and an energy field with moving charge is known as electric power.
• The unit of power is the watt. Generally, electrical power is calculated using Ohm’s law by substituting voltage current and resistance values.
• The formula for the same is P= V*I, where P is power, V is Voltage, and I is current. As it is known that voltage is the product of current and resistance, P also = I2R.

#### Conclusion

Overall, it can be stated that Ohm’s law is a very useful law of physics that simplifies the relationship between varied electrical units. The foundational base of Ohm’s law is that if the current flows through an electric circuit, it will be directly proportional to the voltage in that current.

#### FAQs

• What is Ohm’s law in simple terms?

Ohm’s law details that electric current in any circuit is directly proportional to the voltage in the current; however, it is inversely proportional to the resistance of the circuit.

• What does Ohm’s law state?

Ohm’s law states that the current passing through two points of a conductor is directly proportional to the voltage passing through those two points.

• What are the three forms of Ohm’s law?

The three forms of Ohm’s law are I=V/R, R=V/I, and V=IR, where I is current, V is Voltage, and R is resistance.

• What are the three elements of Ohm’s law?

Current, Voltage, and Resistance are the three elements of Ohm’s Law.

• Why is Ohm’s law important?

Ohm’s law holds high significance because it simplifies the relationship between voltage, current, and resistance in electrical circuits, which eases designing circuits.

A better understanding of Ohm’s Law and its relevant constraints can be understood from the video library and other materials present on the MSVgo application. This application can help the students understand Ohm’s Law in an easy yet efficient manner. The notes present on the application can help the students in answering academic questions.

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