# physics lap homework

answer this qustions and the FILE..

1) In a mass spectrometer, a single-charged particle (charge e) has a speed of 1.0 x 106 m/s and enters a uniform magnetic field of 0.20 T. The radius of the circular orbit is 0.020 m. What is the mass of the particle?

2) A beam of electrons is accelerated through a potential difference of 10 kV before entering a velocity selector. If the B-field of the velocity selector has a value of 0.010 T, what value of the E-field is required if the particles are to be un-deflected?

3) A solenoid with 500 turns is 0.10 m long and carries a current of 4.0 A. What strength of magnetic field will it have at its center?

4) How much current must pass through a 400 turn coil 4.0 cm long to generate a 1.0 T magnetic field at the center?

5) What is the strength of a magnetic field 5.0 cm from a long straight wire carrying 4.0 A of current?

6) A very long straight wire carries a current of 25 A. What is the magnitude of the magnetic field at a distance of 0.15 m from the wire?

7) A high power line carrying 1000 A generates what magnetic field at the ground, 10 m away?

8) How much current must flow for 1.0 x 10-3 T of magnetic field to be present 1.0 cm from a wire?

9) At what distance from a long straight wire carrying a current of 5.0 A is the magnitude of the magnetic field due to the wire equal to the strength of the Earth’s magnetic field of about 5.0 x 10-5 T?

10) What fundamental fact underlies the operation of essentially all electric motors?

A) Opposite electric charges attract and like charges repel.

B) A current-carrying conductor placed perpendicular to a magnetic field will experience a force.

C) Alternating current and direct current are both capable of doing work.

D) Iron is the only element that is magnetic.

E) A magnetic north pole carries a positive electric charge, and a magnetic south pole carries a

negative electric charge.