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Hi, when it comes to physics, I am the stupidiest person on Earth. Thus I have three questions, if someone could walk me through them I would be so thankful it would be ridiculous.

Problem 1.

An electron travels with speed 1.0 x 10^7 m/s between two parallel charged plates. The plates are separated by 1.0 cm and are charged by a 200 V battery. What magnetic field strength and direction will allow the electron to pass between the plates without being deflected?

(for this one I thought that if electrons travel parallel or antiparallel to a magnetic field it will always allow the electron to move. Like I said before I'm a physics idiot)

Problem 2.

The uniform 30 mT fiel points in the positive z direction. An electron enter the region of magnetic field with a speed 5.0 x 10^6 m/s and at an angle of 30 degrees above the xy plane. Find the radius r and the pitch p of the electron's spiral trajectory.

(I have no clue on this one)

Problem 3.

Two springs each have a spring constant of 10 N/m. They are stretched 1.0 cm when a current passes throught the wire. How big is the current?

Note: Magnetic field is 0.5 T, and length of wire is 20cm

(for this one, I found the magnitude of the spring force, multiplied that by 2 since there are two springs. I then set that equal to the F(magnetic field) which is defined by ILB. I then isolated to solve for I. I get an answer of 20A, but my textbook gives an answer of 2.0A. This would lead me to believe my error is small, or that the answer in the book is wrong)

Whowever can help me with these I would be very appreciative, thanks for your time!

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# Homework Help: Magnetic Field Help

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