3932

Physics Magnetism,Magnetic Effects Of Current Level: University

Four long  wires in the figure carry 2.5A current in the  directions indicated. Find the net force per unit length on the wire at the lower left. All sides are 15 cm in length.

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3930

Physics Magnetism,Magnetic Effects Of Current Level: University

Three circular loops of wires of radius R 2R  3R respectively are made into concentric circles. A clockwise current of 3A exists in the innermost and outermost loops. Determine the magnitude and direction in the middle loop if the net field at the center is zero.

3929

Physics Magnetism,Magnetic Effects Of Current Level: University

Solenoid
You have a spool of thin wire that can handle a maximum current of 0.5A. If you could wind the wire into a loop- like coil 20cm in diameter how many turns should the coil have if the magnetic field at its center is to be 2.3 mT at the maximum current.

3927

Physics Magnetism,Magnetic Effects Of Current Level: University

Charge Moving in Magnetic Field
In a certain reion the average radius of curvature of the trajectory of electrons in the Van Allen belt is 300m and the average electron energy is 100keV. What is the value of the earths magnetic field in this region?

3924

Physics Magnetism,Magnetic Effects Of Current Level: University

2 identical wires have a weight per unit length of 1.0 x 10^-4 N/m. The wire are strug parallel to each other one directly above the other with a distance of separation of 0.10m. What current must be present in the 2 wires in order for the upper wire to float above the lower wire. Assume that the wires carry the same current in opposite directions.

3923

Physics Magnetism,Magnetic Effects Of Current Level: University

A long straight wire carries a current of 5.00 A. At one instant  a proton 4.00 mm from the wire travels at 1.50 x 10^3 m/s parallel to the wire and in the same direction as the current. Find the magnitude and direction of the magnetic force on the proton.

3922

Physics Magnetism,Magnetic Effects Of Current Level: University

A porton moves in a circular orbit of radius 14 cm in a uniform magnetic field of 0.35 T directed perpendicular to the velocity of the proton. Find the orbit ( linear) speed of the proton.

3919

Physics Magnetism,Magnetic Effects Of Current Level: University

A rectangular current loop carrent of 8.0 A inthe direction.
Shown: A very long wire is parallel to the sides of the rectangle and carries a current I. The rectangle loop has a length of 0.80 m and its sides are 0.10 and 0.70 m from the long wire. What must be the value of the current I in the long wire to produce an attractive net force of 2.3 x 10^6  N on the rectangle? Show on the diagram below the direction of the current in in the long wire.

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3538

Physics Magnetism,Magnetic Effects Of Current Level: University

 Lorentz force
An electron travels through qa region of space with no acceleration. Which one of the following statements is the best conclusion?
(a) Both E and B must be zero in that region
(b) E must be zero, but B might be non- zero in that region
(c) B must B might both be non-zero but they must be mutually perpendicular
(d) B must be zero but E might be non-zero in that region
(e) E and B might both be non- Zero but they must point in opposite directions.

3537

Physics Magnetism,Magnetic Effects Of Current Level: University

Torque on current  coil
A circular coil consists of 5 loops each of diameter 1.0m. The coil is placed in an external magnetic field of 0.5T. When the coil carries a current of 4.0A a torque of magnitude 3.93N * m acts on it. Determine the angle between the normal to the plane of the coil and the direction of the magnetic field.
(a) 0
(b) 30
(c) 45
(d) 60
(e) 90