Physics Exam II T/F

When a magnetic field exerts a force on a moving charge, the force exerted is along the direction of the magnetic field.

False

Two wires carrying current in the same direction exert an attractice force on each other

True

Transformers are used to decrease the voltage form high voltage power lines into safe levels for residential homes

True

To determine the voltage difference across a circuit element, you should connect a voltmeter in prallel to the element.

True

To decrease the current running through an element in a circuit, you should as a resistor in series with that circuit element.

True

The unit of power is watts

True

THe unit of resistance is amps/meter

False

The unit of magnetic field is ohms

False

The unit of electric potential is volts

True

The unit of current is coulombs

False

The force exerted by a magnetic field on a stationary charge is proportional to the strength of the charge

False

Resistors in series have the same current flowing through them

True

Resistors in parallel have the same voltage drop across them

True

Magnetic fields can produce forces on moving charges, and moving charges produce magnetic fields

True

Lenz’s law states that if a loop has a changing magnetic flux through it, a current is induced in the loop that magnifies (makes bigger) that change

False

If a resistor is added in series with another resistor, the current flowing through the original resistor is decreased.

True

If a resistor is added in parallel with another resistor, the current flowing through the original resistor is increased

False

If a charge moves perpendicular to a uniform electric field, its potential energy increases.

False

Electrically insulating materials are what carries the current in wires

False

Current causes charges to move in wires

False

Capacitors store potential energy in circuits

True

Batteries provide power in the of alternating current

False

A wire loop with current produces a uniform magnetic field that lies in a striaght line, while a straight wire with current produces a magnetic field that loops around it.

False

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