MAGNETISM AND AC

A proton is released such that it has an initial speed of 4.0 x 10⁵ m/s from left to right across the page. A magnetic field of 1.2 T is present at an angle of 30° to the horizontal direction (or positive x axis). What is the magnitude of the force experienced by the proton?

• 4.8 x 10^-25 N

• 1.3 x 10^-19 N

• 3.8 x 10^-14 N

• 7.5 x 10³ N

The force on a charged particle created by its motion in a magnetic field is maximum at what angle between the particle velocity and field?

• zero

• 180°

• 90°

• 45°

Assume that a uniform magnetic field is directed into this page. If an electron is released with an initial velocity directed from the bottom edge to the top edge of the page, which of the following describes the direction of the resultant force acting on the electron?

• out of the page

• to the right

• to the left

• into the page

A stationary positive charge +Q is located in a magnetic field B, which is directed toward the right as indicated. The direction of the magnetic force on Q is:

• rightward

• upward

• downward

• no magnetic force

What would increase the strength of an electromagnet?

• Increasing the amount of current flowing through the wire.
• Inserting a wooden core inside the coil
• Changing the direction of the current
• Decreasing the number of coils of wire

Tags

NGSS.MS-PS2-3

2 ways to increase the magnetic force of an electro-magnet

• Increase the current flow, reduce the number of coils
• Increase the voltage, decrease the number of coils
• Increase the number of coils and the current flow
• Spread out the coils, replace iron core with rubber.

Tags

NGSS.HS-PS2-5

The period of a wave is

• the same as frequency
• time required to complete one cycle
• expressed in amperes
• none of the above

A current-carrying wire of length 50 cm is positioned perpendicular to a uniform magnetic field. If the current is 10.0 A and it is determined that there is a resultant force of 3.0 N on the wire due to the interaction of the current and field, what is the magnetic field strength?

• 0.60 T

• 1.5 T

• 1.8 x 10^-3 T

• 6.7 x 10^-3 T

An electron is moving at a speed of 6.0 x 10⁶ m/s at an angle of 30° with respect to a uniform magnetic field of 8.0 x 10^-4 T. What is the radius of the resulting helical path? (m_e = 9.11 x 10^-31 kg, q_e = 1.6 x 10^-19 C)

• 8.5 cm

• 4.3 cm

• 3.7 cm

• 2.1 cm

1) A bar magnet is at rest, next to a fixed electromagnet. In which direction will the bar magnet move when switch S is closed?

• to the left

• to the right

• up the page

• down the page

Tags

NGSS.HS-PS2-5

NGSS.HS-PS3-5