Inductors and inductance and some other stuff

[Marioqwe]

Homework Statement

A certain solenoidal inductor has a magnetic flux of 835 μWb through each loop of its coil when the current flowing through it equals 0.600 A. If the solenoid has 125 loops, what is its inductance?

Homework Equations

L = [(N)(magnetic flux)]/I

The Attempt at a Solution

L = (8.35e-4)(125)/0.6

L = 0.17H

Is there anything wrong?

Homework Statement

A sailboat with an aluminum mast 22.5 m high is sailing eastward along the equator at a speed of 3.66 meters per second. The Earth's magnetic field at the ship's location is 5.50×10−5 T, horizontal and directed due north. What is the induced potential difference between the top and bottom of the mast?

Homework Equations

V=LvB

The Attempt at a Solution

V = (22.5)(3.66)(5.5e-5)
V = 0.0045T

It marks me wrong

Homework Statement

You have three parallel conducting rods. Two of them are very long, and the third is 10.0 m long, with a weight of 36.0 N. You wish to conduct the following levitation demonstration: The two long rods will be placed in a fixed horizontal orientation at the same height, 10.0 cm apart. The third rod is to float above and midway between them, 10.0 cm from each one (from an end view, the three rods will form the vertices of an equilateral triangle). You will arrange to pass the same current I through all three rods, in the same direction through the two "supporting" rods and in the opposite direction through the "levitating" rod. What is the magnitude I of the current that will maintain this astounding configuration?

Homework Equations

F = μ0(I1)(I2)(L)/[2(pi)R]

The Attempt at a Solution

I'm really confused with this one. I still don't know how to approach it.




I asked my teacher for help and it seems that I'm really dumb I can't even understand this simple problems. He turned me down: "I am giving you the simplest problems in the world, and you fail them on a technicality." I'm having a hard time figuring out some of them.

Any help is appreciated

Thanks

mario

 

[anathema]

123

Dear mario123,

It's understandable to feel discouraged when faced with difficult problems, but don't be too hard on yourself. It takes time and practice to fully understand and master scientific concepts. Here are some tips to help you approach these problems:

1. Make sure you understand the basic principles involved in the problem. In the first problem, for example, you need to know the equation for inductance and how to apply it. Take some time to review these concepts before attempting the problem.

2. Write down all the given information and identify what you are trying to solve for. This will help you see the big picture and organize your thoughts.

3. Break down the problem into smaller, more manageable steps. In the second problem, for instance, you need to use the equation V=LvB, but you also need to know the length of the mast and the strength and direction of the Earth's magnetic field. Write down each step and make sure you understand how they all fit together.

4. If you get stuck, try looking at similar examples or asking for help from a friend, teacher, or tutor. Sometimes seeing a problem in a different context can help you understand it better.

Remember, it's okay to make mistakes and ask for help. Keep practicing and you will improve. Good luck!