Cathode rays are now known to be
A)
electrons.
B)
visible light rays.
C)
protons.
D)
x-rays.
E)
short wavelength light rays.
A
You might also like to view...
Today, the leading hypothesis for the existence of hot Jupiters is that they formed in their outer solar systems and then migrated inward. Why did this hypothesis gain favor over alternative ideas?
What will be an ideal response?
Why do we see essentially the same face of the Moon at all times?
A) because the other face points toward us only at new Moon, when we can't see the Moon B) because the Moon does not rotate C) because the Moon's rotational and orbital periods are equal D) because the Sun illuminates only one half at a time E) because the Moon has a nearly circular orbit around Earth
When Copernicus first created his Sun-centered model of the universe, it did not lead to substantially better predictions of planetary positions than the Ptolemaic model. Why not?
A) Copernicus used perfect circles for the orbits of the planets, though they are actually ellipses. B) Copernicus placed the planets in the wrong order going outward from the Sun. C) Copernicus misjudged the distances between the planets. D) Copernicus placed the Sun at the center, but did not realize that the Moon orbits Earth.
A constant magnetic field is applied perpendicular to the plane of a square, single-turn coil with each side equal to 15 cm. If the area of the coil decreases at a rate of 0.20 m2/s, an emf of 20 mV is induced in that coil
What is the strength of the magnetic field applied to the coil? A) 0.10 T B) 0.20 T C) 0.30 T D) 0.40 T E) 0.50 T