Physical Science Test #3

A 70-dB sound relative to a 40-dB sound is more intense by a factor of

1000

A charge of +Q attracts a charge of -Q 1 cm away with a force of F. Another charge of +Q is placed next to the first one. The force on the charge of -Q is now

2F

When the voltage across a certain resistance is V, the power delivered is P. If the voltage is doubled to 2V, the power delivered becomes

4P

Relative to the radio signals sent out by a spacecraft headed away from the earth, the signals that are received on the earth have

A lower frequency

The property of light waves that leads to the phenomenon of color is a. speed

Frequency

An object has a positive electric charge whenever

It has a deficiency of electrons

A compass needle tends to

Line up parallel to a magnetic field

The lower the frequency of a sound wave, the

Longer it's wave length

The volt is the unit of electric

Potential difference

Two charges of +Q are 1 cm apart. If one of the charges is replaced by a charge of -Q, the magnitude of the force between them is

The same

Sound waves whose frequency is 300 Hz have a wavelength relative to sound waves in the same medium whose frequency is 900 Hz that is

Three times as great

Direct electric current cannot be used to operate

Transformers

The primary coil of a transformer is connected to a source of alternating current of voltage V. The voltage of the secondary current is

a. lower than V. b. equal to V. c. higher than V. Correct D. Any of the choices, depending on the ratio of turns in the transformer coils.

In an electromagnetic wave, the electric field is

perpendicular to both the magnetic field and the wave direction

In a transverse wave, the individual particles of the medium move

perpendicular to the direction of travel

An example of a purely longitudinal wave is a

sound wave

The watt, the unit of power, is equal to the

(volt)(ampere)

The amplitude of the wave shown in the figure is

B

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

Electric Charge

A kilowatt hour is a unit of

Energy

A sound wave whose frequency is 50 Hz

has a relatively long wavelength

The charge on an electron

is always the same

Protons and electrons have different masses. When they are the same distance apart, the electric force between two electrons

is the same as the force between two protons

The greater the decibel (dB) level of a sound wave, the

louder it is