Why does voltage increase in a denser solenoid

[A_curious_Homosapien]

I have seen and been told that the voltage increases in a solenoid with more number of turns. Why does the voltage increase, and what is the point of doing this because the current should remain the same since resistance is increasing at the same time and that would balance the equation V = I*R. Right?

[swansont]

The voltage generated is proportional to the number of turns. Every loop counts toward the area that is experiencing the changing magnetic field.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/farlaw.html

The reason for more turns depends on the application. The voltage might be the important factor.

You might be using the solenoid to create a magnetic field by supplying it with current, and a longer solenoid has a more uniform field inside of it. You could be current-limited but not voltage-limited, and want a stronger field.

[studiot]

5 hours ago, A_curious_Homosapien said:

I have seen and been told that the voltage increases in a solenoid with more number of turns. Why does the voltage increase, and what is the point of doing this because the current should remain the same since resistance is increasing at the same time and that would balance the equation V = I*R. Right?

I'm not sure I understand what you are getting at here.

Surely solenoids are beyond grade 10 ?

 

Yes as the length of wire making the solenoid increases so will the resistance (I think that is grade 10) but the resistance of winding wire in any coil is generally insignificant compared to the magnetic effect causing an opposition to change of current, which is called reactance.

I don't think reactance comes into it until later grades, but I will explain if you wish.

Swansont mentioned that each turn or loop of the coil adds to this effect so the number of coils is significant.

This is rather like (but not exactly the same as) the force that can be generated by a pressure depends upon the area the pressure acts over.
The larger the area the greater the force a given pressure will generate.
You have probably done something like this in mechanics with say the principle of the hydraulic lift

[A_curious_Homosapien]

5 hours ago, studiot said:

Surely solenoids are beyond grade 10 ?

Well they are over here India, we have been taught about the pattern of magnetic field line in a solenoid, electromagnetic induction and Faraday's Law.

 

5 hours ago, studiot said:

but the resistance of winding wire in any coil is generally insignificant compared to the magnetic effect causing an opposition to change of current

So does this mean that, the rate of increase of Voltage is higher than the increase in resistance so the current also increases to keep the equation V = I*R true. Right?

10 hours ago, swansont said:

Every loop counts toward the area that is experiencing the changing magnetic field.

What if instead of solenoid I decided to use a torus. Wouldn't that be great? Torus is a kind of solenoid with infinite amount of turns, and a copper torus would give maximum possible voltage.

Edited September 1, 2021 by A_curious_Homosapien

[swansont]

10 hours ago, A_curious_Homosapien said:

What if instead of solenoid I decided to use a torus. Wouldn't that be great? Torus is a kind of solenoid with infinite amount of turns, and a copper torus would give maximum possible voltage.

It’s not infinite, and the application might dictate the desired geometry.