# Homework Help: Magnetic Flux Through a Square Loop

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1. Mar 4, 2017

### ilovejava

1. The problem statement, all variables and given/known data
A loop of wire in the form of a square 1.50 m on each side, its plane makes an angle of 40.0° with a uniform magnetic field of 0.95 T. What is the magnetic flux through the loop?

2. Relevant equations
Φ = BAcosθ
A = s^2
3. The attempt at a solution
I found the area of the square using A = s^2 which returns 2.25m. Then I just plugged in the values provided in the question making sure to use 40°. I got Φ = 1.64Wb but the answer is 1.37Wb

2. Mar 4, 2017

### TSny

In the formula Φ = BAcosθ, can you describe in words the meaning of the angle θ? What particular angle does it represent?

The angle of 40.0° given in the statement of the problem might not be the angle represented by θ in the formula.

3. Mar 4, 2017

### ilovejava

The angle in the formula is the angle the loop makes with respect to the magnetic field. If the angle was 90 the the magnetic flux would be zero because no magnetic field lines would pass through the loop.

4. Mar 4, 2017

### TSny

θ is not the angle that the plane of the loop makes to the magnetic field.

The picture below shows the case where the plane of the loop makes a 90o angle to the B field.

Would you say that the flux through the loop is zero here?

5. Mar 4, 2017

### ilovejava

No the flux through the loop is not zero. I guess it's the angle made between the normal of the loop and the magnetic field?

6. Mar 4, 2017

### TSny

Yes, θ in the formula is the angle between the normal of the loop and the magnetic field.