I'm having a lot of trouble with the following questions. I was wondering if someone could steer me in the right direction and tell me what I'm doing wrong.(adsbygoogle = window.adsbygoogle || []).push({});

I suppose my biggest problem is I don't understand how to do these without knowing the number of turns in the coil. Here's what I've done so far:

1. [GianPSE3 29.P.002.] A 20 cm diameter circular loop of wire lies in a plane perpendicular to a 0.80 T magnetic field. It is removed from the field in 0.10 s. What is the average induced emf?

2. [GianPSE3 29.P.005.] A 8.0 cm diameter loop of wire is initially oriented perpendicular to a 1.2 T magnetic field. It is rotated so that its plane is parallel to the field direction in 0.40 s. What is the average induced emf in the loop?

3. [GianPSE3 29.P.006.] A 7.6 cm diameter wire coil is initially oriented so that its plane is perpendicular to a magnetic field of 0.63 T pointing up. During the course of 0.12 s, the field is changed to one of 0.25T pointing down. What is the average induced emf in the coil?

Any help or suggestions would be greatly appreciated!! Thanks so much!!

Work is in attatched pictures! Thanks!

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# Induced EMF ~ Faraday's Law/Lenz's Law

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