Exam 2 Flashcards
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?
90 degrees
A proton moves across Earth’s equator in a northeasterly direction. At this point the Earth’s magnetic field has a direction due north and is parallel to the surface. What is the direction of the force acting on the proton at this instant?
Out of the Earth’s surface
If a proton is released at the equator and falls toward the earth under the influence of gravity, the magnetic force on the proton will be
East
A horizontal wire of length 3.0 m carries a current of 6.0A and is oriented so that the current direction is 50 degrees Sof W. The earth’s magnetic field is due north at this point and has a strength of .14 E-4. What is the direction of the force on the wire?
Toward Earth’s surface
A metal rod is falling toward the surface of the earth near the equator. As it falls, one end of the rod becomes positively charged due to motional emf of the rod through the Earth’s magnetic field. The rod is oriented so that:
The rod is horizontal with positive end toward the east.
Two loops of wire are arranged so that a changing current in one will induce current in the other. If the current in the first is increasing clockwise by 1.0 A every second, the induced current on the second loop will
stay constant.
Basic function of electric generator is which of the following conversion processes?
Mechanical energy to electrical
Basic function of electric motor is which of the following conversion processes?
Electrical energy to mechanical
In an AC series circuit, the current in a pure resistor differs in phase with the applied voltage by what angle?
Zero
In a capacitor in an AC circuit, the voltage
Lags the current by 90 degrees
In an AC series circuit the voltage in the inductor differs in phase with the voltage in the capacitor by what angle?
180 degrees
The current in an inductor connected to an AC voltage source lags voltage. This lag is caused by the
voltage across the coil
The wave particle duality of light means in the same experiment
Light will not act like either a wave or a particle
When you view your image in a hand held mirror, if you move the mirror away at a speed v, the image appears to
move away at 2v
As a monochromatic light ray is transmitted through an air to glass boundary, what happens to the wavelength?
Decreases
What will happen to a light ray incident on a glass to air boundary at greater than the critical angle?
Total reflection
A deuteron with the same charge but twice the mass of a proton moves with speed of 3.0 E 5 perpindicular to a uniform magetic field of .20 T. Which of the paths below would it follow?
Circular path of 3.1 radius
Two insulated carrying straight wires of equal length are arranged so A carries current north and B carries current east. The wires cross at midpoint separated only by insulation. Which is true?
There are forces, but the net force on each wire is zero.
A bar magnet falls through a loop of wire with constant velocity. North pole enters first. As south pole leaves wire loop, induced current will be
Clockwise
Two parallel conductorss are carrying current in opposite direction. Currents are non zero and not necessarily equal. The magnitude of the magnetic field midway between them is 40 microT. If one of the currents has its direction reversed, what is the resulting magnitude of the magnetic field midway between them?
Value greater than 40 micro T
In a circuit made up of inductor, resistance, ammeter, battery, and switch in series at which of the following times after the switch is closed is the rate of current increase greatest?
Zero
A circular current loop is placed in an external magnetic field. How is the torque related to the radias of the loop?
Directly proportional to radius squared
A bar magnet is held above the center of a conducting ring in the horizontal plane. The magnet is dropped so it falls lengthwise toward the center of the ring. Will the falling magnet be attracted toward the ring or be repelled by the ring due to magnetic interaction of the magnet and ring?
It will be repelled
