Physics II Test 3

A charged particle of mass 0.0060 kg is subjected to a 7.0-T magnetic field which acts at a right angle to it motion. If the particle moves in a circle of radius 0.10 m at a speed of 4.0 m/s, what is the magnitude of the charge on the particle?

0.034 C

An Ideal solenoid 20 cm long is wound with 5000 turn of very thin wire. What strength magnetic field is produced at the center of the solenoid when a current of 10 A flows through it?

0.31 T

A conducting rod of length l=25 cm is placed on a U-Shaped metal wire that is connected to a lightbulb having a resistance of 8.0 Ω, as shown in the figure. the wire and the rod are in the plane of the page. A constant uniform magnetic field of strength 0.40 T is applied perpendicular to and into the paper. An applied external force pulls the rod to the right with a constant speed of 6.0 m/s. What is the magnitude of the emf induced in the rod?

0.60 V

The secondary coil of an ideal neon sign transformer provides 7500 V at 10.0 mA. The primary coil operates on 120 V. What current does the primary draw?

0.625 A

A straight wire carries a current of 10 A at an angle of 30 with respect to the direction of a uniform 0.30-T magnetic field. Find the magnitude of the magnetic force on a 0.50-m length of the wire

0.75 N

As shown in the figure, a wire and a 10-Ω resistor are used to form a circuit in the shape of a square with dimensions 20 cm by 20 cm. A unifrom but non-steady magnetic field is directed into the plane of the circuit. The magnitude of thee magnetic field is steadily decreased from 0.30 T to 0.10 T in a time interval of 72 ms. What is the induced current in the circuit, and waht is its direction through the resistor?

11 mA, from b to a

The magnetic flux through a coil changes steadily from 4.0 x 10^-5 T∙ m^2 to 6.0 x 10^-5 T ∙ m^2 in 0.10 s. What emf is induced

2.0 x 10^-4 V

An electron moves with a speed of 4.0 x 10^4 m/s perpendicular to a uniform magnetic field of magnitude 0.50 T. What is the magnitude of the magnetic force on the electron?

3.2 x 10^-15 N

How much current must flow through a long straight wire for the magnetic field strength to be 1.0 mT at 1.0 cm from a wire?

50 A

The wavelength of an electromagnetic wave is 600 nm. What is its frequency?

500 x 10^12 Hz

A coil lies flat on a level tabletop in region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the induced current in this coil as the field increases?

Clockwise

A charged particle is injected into a uniform magnetic field such that its velocity vector is perpendicular to the magnetic field vector. The particle will

Follow a circular path

A transformer is a device that operates

Only an AC

Which on of the following types of electromagnetic wave travels through space the fastest?

They all travel through space at the same speed.

A vertical wire carries a current straight up in a region where the magnetic field vector points toward the north. What is the direction of the magnetic field on this wire?

Toward the west

A charged particle moves with its velocity perpendicular to a magnetic field. The field acts to change the particle's

Velocity

Faraday's law of induction states that the EMF induced in a loop of wire is proportional to

change in magnetic flux divided by time

Lenz's law is a consequence of the law of conservation of

energy

A proton, moving north, enters a magnetic field. Because of this field, the proton curves downward. We may conclude that the magnetic field must have a component

towards the east

Breaking a bar magnet in half will produce

two bar magnets