# Magnetic Flux

1. Dec 30, 2014

### Samurai44

1. The problem statement, all variables and given/known data
Uploaded the question below , Part B

2. Relevant equations
Φ=NBA
EMF= (delta)Φ/(delta)t
V=IR

3. The attempt at a solution
so i found the area (0.25x0.3) and then divided by two (=0.0375m^2) , then found Φ=80x1.4x0.0375=4.2wb
However , in the marking scheme they multiplayed by the speed instead of area !!

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2. Dec 30, 2014

### BvU

So, you calculated $\Phi$. But for the emf you need $d\Phi\over dt$. Is the step from one to the other unclear to you ?

3. Dec 30, 2014

### Samurai44

i know i have to use dΦ/dt , thats why i calculated Φ .. couldnt get how they found 0.7v

4. Dec 30, 2014

### BvU

Area with magnetic field within the loop is xy . x is constant, 0.25 m. At t=0 y = 0.15 m . When the coil is moving, y decreases by 2 m/s

5. Dec 30, 2014

### Samurai44

so its like we make change of "y" over time equals to the speed ? since speed = distance covered / time taken

6. Dec 30, 2014

### BvU

That is exactly what it is !