Introduction to Solenoid & Toroid
In this article, students will learn about solenoids and toroids which work on the basis of the electromagnetism property of Physics.
What is a Solenoid?
A solenoid consists of a coil of wires which when subjected to electricity, acts as a magnetic substance. The wires are wrapped around a magnetic core. The wires are enamelled, therefore, the wires themselves are insulated from each other. Each turn is enclosed in circular loops. The magnetic field generated is equivalent to the total magnetic field generated by the solenoid. The total magnetic field is given by the vector sum of force produced by each turn and can be given by the following equation:
F = µ0nI
where n is the number of wires per turn per unit length, l is the amount of current flowing through the wire.
Types
Electric principles do not differ for different types of the solenoid, their designs, functions or material are supposed to differ. The different types of solenoids are:
DC D-Frame Solenoid
AC Laminated Solenoid
DC C-Frame Solenoid
Rotary Solenoid
Linear Solenoid
What is a Toroid?
A toroid is basically a solenoid bent in a circular shape. It is a hollow circular body with many turns of insulated wire which are closely wound with very little space in between two turns. The magnetic field inside and outside the toroid is zero. The direction of the magnetic field is always clockwise and can be determined by the right-hand thumb principle. The magnetic field equation inside a toroid can be given as:
B = \[\frac {\mu NI} {2\Pi r}\]
where N is the number of turns in the coil, r is the radius of the toroid turns, and l is the current flowing through the coils.
Differences and similarities
Differences
The solenoid is cylindrical in shape while a toroid is circular in shape.
In a solenoid, the magnetic field is formed outside while in a toroid, the magnetic field is formed inside.
The magnetic field in a solenoid is uniform, however, it is not the same for a toroid.
Similarities
Both the solenoid and the toroid follow the principles of electromagnetism.
Both the solenoid and the toroid act as magnets when electricity is passed through them.
The magnetic fields produced by both of them are always equal.
Applications
Solenoids have many applications in everyday life. These applications are given as follows:
Solenoids are used in locking systems that are controlled electrically. It works until electricity flows through it and the doors remain locked.
Solenoids find their applications in dialysis machines and in other kinds of medical devices.
Solenoids are also found in industrial devices such as operations used in pinching, rotating, etc.
Interested to know more about solenoids and toroids? Visit Vedantu's website or download the app where you can get study materials, notes, important questions and a lot more for absolutely free of cost which you can download in the PDF format and study them anytime, anywhere.
FAQs on Solenoid and Toroid
1. What is the Nature of Magnetic Field Inside a Solenoid?
A magnetic field inside a solenoid is always uniform, meaning that it exhibits the same magnetic force throughout all parts of the coil.
2. Is a Magnetic Field Inside a Solenoid Uniform or Non-Uniform?
Magnetic field inside a solenoid is uniform. However, this is not the case for toroids, where the magnetic field is usually non-uniform in nature.
3. What is a Solenoid in Physics?
A solenoid is a cylindrical device with copper wires wound around it. Solenoids assume magnetic properties when an electric current passes through it.
4. What are the differences between solenoid and toroid?
There are a few distinct differences between a solenoid and a toroid which can be enumerated as follows:
A solenoid is cylindrical in shape whereas a toroid is circular in shape.
In a solenoid, the magnetic field is formed outside while in a toroid, the magnetic field forms within the toroid.
In a solenoid, the magnetic field is uniform. In a toroid, the magnetic field is not uniform.
In a solenoid, the magnetic field is denoted by B = µ0nI. In a toroid, the magnetic field inside and outside the toroid is zero. However, the magnetic field within the toroid is given by B = \[\frac {\mu NI} {2\Pi r}\] .
5. What are the similarities between solenoid and toroid?
There are a few similarities between a solenoid and a toroid:
Both the solenoid and toroid act according to the principles of electromagnetism to be able to function properly.
The magnetic fields produced by them are always equal.
When subjected to electricity, both the solenoid and the toroid act as magnets.
6. What are the different types of solenoids?
The different types of solenoids are as follows:
DC D-Frame Solenoid
AC Laminated Solenoid
DC C-Frame Solenoid
Rotary Solenoid
Linear Solenoid
7. What are the applications of the solenoid?
Solenoids have a wide range of practical applications, some of which can be summed up as follows:
In locking systems for secure doors, solenoids are used and the doors are closed as long as electricity passes through them.
In medical devices such as in a dialysis machine, solenoids are used.
Devices of industrial importance are involved in operations like pinching, rotating and holding.
8. What is the magnetic field like inside a toroidal solenoid?
Inside a toroidal solenoid, the magnetic field is independent of the radius of the toroid. Outside the toroid, the magnetic field is zero.
