Work functions of tungsten and sodium are 4.4 eV and 2.3 eV respectively. If threshold wavelength of sodium is 5460 A, then threshold wavelength of tungsten is
(a) 11360 A
(b) 8000 Å
(c) 6000
Å
(d) 2840 A
o​

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

Select the three ways that the parallel-plate capacitor differs from a car battery.

What is an electric motor? explain its operation. 2-3 sentence