Electricity & Megnetism

Resistance and resistivity difference                     Resistance                          Resistivity  It is the opposition to the flow of electric current through a conductor. It is the resistance of a meter cube of a wire. Its SI unit is ohm ( Ω ). Its ...

Galvanometer and ammeter are both current measuring devices.The galvanometer is used to measure very small current while ammeter is used to measure very large current up to 10 A. Now! We study in detail about these two instruments and we will also see the difference between galvanometer and ammeter. What is galvanometer? It is an electrical device which is used to ...

An ammeter is an electrical device which is used to measure the current. It is the modified form of the galvanometer. It is a low resistance galvanometer. It is always connected in series with the circuit to measure current. An ideal ammeter has zero resistance. Meter movement The portion of galvanometer whose motion causes the needle of the device to ...

What is electric field? Coulomb’s law for the force between charges encourages us to think in terms of action at a distance represented as charge  ↔ charge. Again introducing the field as an intermediary between the charges, we can represent the interaction as: charge ↔  field ↔ charge Therefore the first charge sets up an electric field, and the second charge ...

There are three types of magnetic materials.Examples of magnetic materials are: Paramagnetic materials Diamagnetic materials Ferromagnetic materials Paramagnetic substances paramagnetic substances are those which are attracted by magnets and when placed in a magnetic filed move from weaker to stronger parts of the field. Paramagnetic materials examples Familiar examples are: aluminum maganese platinum, crown glass solution of salts of iron ...

Semiconductors Semiconductors are those materials which are neither good conductors nor good insulators.Their conductivity is intermediate between conductors and insulators.Silicon and germanium are semiconductor elements, at room temperature.The conducting of semiconductors in charged by temperature applied voltage or incident light.Pure silicon or germanium are poor conductors but by doping with impurities charge the conductivity at a lot.The temperature coefficient of ...

What is the solenoid? The solenoid is defined as:”A long tightly wound cylindrical conducting wire is called solenoid.” Inductance of a solenoid Now we will prove “Inductance of a solenoid derivation”. Consider a solenoid having n turns per unit length.When current passes through the solenoid, magnetic field is produced inside the solenoid which is directed along the axis of the ...

What is Kirchhoff’s Voltage Law? Kirchhoff’s voltage law is a fundamental circuit law that states that the algebraic sum of all the voltages around a closed path is zero or, in other words,the sum of the voltage drops equals the total source voltage. Kirchhoff’s loop rule In an electric circuit, the voltages across the resistors(voltage drops) always have polarities opposite ...

 State Joule’s law of heating “The heat produced in a conductor is: (1) Directly proportion the square of current passing through the conductor,(H ∝ I²) keeping R and t constant; (2) Directly proportion to the resistance of the conductor (H ∝ R) keeping I and t constant;and (3)Directly proportional to the time of flow of current (H ∝ t) keeping I and R ...

Gravitational force is the force by which earth attracts other objects by mass. It is a conservative force. While electrostatic force is the force of an object due to charge. It is also conservative force. These two forces belong to the four fundamental forces of nature. Now! We see the difference between gravitational force and electric force in tabular form. ...