To calculate the frequency of an electromagnetic wave, you need to know the speed of the wave and its
a. wavelength.
b. intensity.
c. refraction.
d. amplitude.

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.

Which of the following is not a transverse wave? a) soundb) lightc) radiod) all of thesee) none of these

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current