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Electricity & Megnetism

Inductance of a solenoid derivation

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 ...

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Kirchhoff’s voltage and current law with examples

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 ...

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Joules law of heating equation

 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 ...

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Difference between gravitational force and electrostatic force

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. Gravitational force Vs Electric ...

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Energy stored in a capacitor equation derivation and problems

Energy stored in a capacitor equation Consider a capacitor with the capacitance ‘C’ ,which is connected to the battery of emf ‘V’ .If ‘dq’ charge is transferred from one plate to other,then the work done ‘dW’ will be: dW =V dq This work done is stored in the form of electric potential energy ‘dU’ dU =V dq When the capacitor ...

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Difference between polar and non polar dielectric materials

Capacitance with dielectric formula Consider a parallel plate capacitor which is connected with a battery of emf ‘V’ .Let ‘A’ is the area of each plate and ‘d’  is separation between the plates. If ‘q’ charge is stored in the capacitor when there is vacuum or air as medium between the plates ,then: q= CV Where ‘C’ is the capacitance ...

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Difference between thermistor and thermocouples

Thermistor definition A thermistor is a type of  variable resistor that is temperature sensitive . How thermistor works? When its temperature coefficient is negative,the resistance changes inversely with temperature. When its temperature coefficient is positive the resistance changes directly with temperature. The resistance of a photo-conductive cell changes with a change in light intensity.This cell also has a negative temperature coefficient. Symbols for ...

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formula for total capacitance in series and parallel combination

Formula of equivalent capacitance in series Series combination when capacitors are connected in series,the total capacitance is less than the smallest capacitance value because the effective plate separation increases.The calculation of total series capacitance is analogous to the calculation of total resistance of parallel resistors. This type of combination has the following characteristics: Each capacitor has the same charge across ...

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Inductor and inductance:types and applications

What is Inductor and what does it do? When a length of wire is formed into a coil,it becomes a basic inductor. The term coil and inductor are used interchangeably.Current through the coil produced an electromagnetic field, as illustrated. The magnetic lines of force around each loop (turn) in the winding of the coil effectively add to the lines of ...

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Magnetic flux density:Definition,unit,formula and applications

Magnetic Flux definition The group of force lines going from the north pole to the south pole of a magnet is called the magnetic flux, symbolized by Φ (the Greek letter phi). The number of lines of force in a magnetic field determines the value of the flux. The more lines of force, the greater the flux and the stronger the magnetic ...

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