Voltage drop across Inductor – formula & polarity

There are three basic passive circuit components – Resistor, Capacitor and Inductor. One can find the voltage drop across a resistor simply by using Ohm’s law of current electricity. In another article, we have discussed different ways to find the voltage drop across a capacitor. Here I’m going to explain the formula and polarity of … Read more

Why are metals good conductors of electricity and heat?

In current electricity, we became to know that the flow of electric charges is electricity. Again, from Thermodynamics, we know that heat is an energy that can flow from one part to another part of a substance. You may have noticed that a wiring of copper (Cu) wire is used in our home or office … Read more

Formula of Power factor in electrical circuit

Power factor is an important parameter of an electrical circuit. To deal with a circuit, we need to know how much power is to be supplied to its components so that the circuit works. Because the dissipation of power in a circuit may not be the same as that of real power supplied by the … Read more

Unity Power factor in electrical circuit | formula & concept

We already have discussed the Power factor of an electrical circuit and how to calculate the power factor, etc. You might have heard the term unity power factor while dealing with the power in electric AC circuits. In this article, we are going to discuss the concept and formula of Unity Power factor of an … Read more

Voltage drop across capacitor – formula & concepts

A Capacitor is an important component in an electrical circuit. We have discussed different types of capacitors in other articles. Like other components (resistors, inductors), a capacitor also offers opposition to the current flow (Direct current only) through it. That means it generates impedance. Ohm’s law tells us that an impedance causes a voltage drop. … Read more

Impedance of Inductor formula | Inductive reactance

Electrical components like resistors, capacitors, inductors and their combination offer an electrical impedance to the current flow. Ohm’s law gives an expression for the impedance (resistance) of a resistor in terms of current and voltage. But how to find the impedance of an inductor? In this article, I will explore the formula for the impedance … Read more

Formula for impedance in electronics (RL RLC & LC circuit)

Impedance is a frequently used term in electronics and physics. We already have discussed the resistance of a conductor in another article. Impedance is almost the same as resistance. But there are some differences in the presentation of impedance. In this article, we are going to discuss the definition, units and formula for impedance in … Read more

Combination of resistors in series and parallel connection

Suppose you have two carbon resistors of 2 ohms each, but you need 1 ohm resistance to connect in a circuit. What will you do if there are no other sources to collect a resistor of resistance 1 ohm? Again, what will you do if you need 4 ohms to use? Yes, we need to … Read more

MCQ on current electricity for class 12 CBSE PDF

In recent exam pattern of class 8, 10 and 12, MCQ and short questions carry majority marks. In this context multiple choice questions are very much important to secure a good score in exams. Students need to find MCQs from the textbooks. But most of the students fail to gather majority of inside questions. Therefore, … Read more

Expression for drift velocity of free electrons

If an external electric field is applied across a conductor, free electrons move in the conductor. The velocities of all the electrons are not the same at every point in the conductor. Therefore, we need to consider the average value of the velocities of the electrons. It is nothing but the drift velocity. In this … Read more