Kitab Nagri

What is Radio and its Working   Introduction:   A radio is a device for receiving and sending Speech or music over large areas by electromagnetic signals.       Working:   Transmission: Information is sent out into the atmosphere from a Transmitting station. When someone speaks in the microphone at the radio station, sound…

Fleming’s Left Hand Rule   Place the fore finger and the second finger of the left hand at right angles. Then, if the fore finger points in the direction of the magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of the motion.  …

Electric Bell & its works   Construction: An electric bell consists of an electromagnet. One end of the winding is connected to a terminal (T1). The other end is connected to a Spring, which is mounted on a soft iron strip called “Armature.” A rod is attached to the armature with its free end having…

What is Telegraph and its Working   A telegraph is a device that is used to send and receive messages between two distant points.   Construction:   An electric telegraph consists of a battery that is connected to a buzzer through the tapping key, There is only one wire between the buzzer and the tapping…

What is Electromagnet in Physics   If soft iron is inserted in the core of a solenoid, the magnetic field due to the current in the solenoid is multiplied by thousands. When the current is switched off, the magnetic field disappears. Such a magnet which can be energized by an electric current is called an…

What are npn and pnp transistors   npn Transistor:   The npn transistor has a thin piece of p-type substance sandwiched between two pieces of n-type semiconductors.   pnp Transistor: The pnp transistor has a thin piece of n-type substance sandwiched between two pieces of p-type semiconductors.   decide which screen diagonal will be more…

What is Transistor   A transistor is a semiconductor, which consists of a thin central layer of one type of semiconductor material sandwiched between two relatively thick pieces of the other type of semiconductor. The central part is known as the base (b) and the pieces at either side are called the emitter (e) and…

What is Solenoid in Physics   A call of insulated copper wire in the form of a long cylinder is called a solenoid.   Magnetic Field of a Solenoid:   When an electric current is passed through a solenoid a magnetic field is produced which is very similar to that of a bar magnet. One…

What is Rectifier   A rectifier is a device that converts Alternating current into Direct current.   The quarantine continues and fewer and fewer people are on the streets. Someone for the first time in years went on a forced vacation, someone began to work remotely. What to do with yourself during quarantine at home?…

What is Right Hand Rule   The direction of the magnetic field can be determined by the following rule: Imagine the wire to be grasped in the right hand with the thumb pointing along the wire. The direction of the fingers will give me direction of the magnetic lines of force.   How to write…