Phyisics
A wave travels an average distance of 1 meter in 1 second with a frequency of 1 hertz. Its amplitude is
1 m
A volume of air has a temperature of 0 degrees Celcius. An equal volume of air that is twice as hot has a temperature of about?
273 C
At a concert the oboe is playing a long steady note as you walk away from the stage at an accelerating velocity toward the rest room. The pitch of the sound that you hear, is
decreasing
An electron is shot through a spot somewhere between the ends of a horseshoe magnet. The electron
direction is changed
Firefighters find that the temperature of burning material is best lowered when water is
sprayed as a fine mist
Ice tends to form first at the
surface of bodies of water
A difference between electric forces and gravitational forces is that electrical forces include A. separation distance. B. repulsive interactions. C. the inverse square law. D. infinite range. E. none of these.
B
15) The phenomenon of beats results from sound A) refraction B) reflection C) interference D) all of these E) none of these
C
8) Stretch a copper wire so that it is thinner and the resistance between its ends A) decreases. B) remains unchanged. C) increases.
C
Transformers use ac so there will be the required:
Change in magnetic field for operation
If you plug an electric toaster rated at 110 V into a 220-V outlet, the current in the toaster will be about A) half what it should be. B) the same as if it were plugged into 110 V. C) more than twice what it should be. D) twice what it should be.
D
The technology for orbiting solar power plants A) awaits the next century. B) already exists. C) is theoretically impossible.
already exist
Double the frequency of sound and you also double its
none
An iron nail is more strongly attracted to the north or south pole of a magnet?
north or south pole. no difference really
If the primary of a transformer is connected to a dc power source, the transformer would have a voltage output at a higher efficiency than with an ac source. that is also dc. only while being connected or disconnected. none of the above the same.
only while being connected or disconnected
5) Both black and white road surfaces radiate energy. At the end of a starry night (no clouds) the warmer road surface will be A) the white surface. B) the black surface. C) neither -- there is no difference.
the white surface
During a very cold winter, water pipes sometimes burst. The reason for this is
water expands when freezing