In the circuit diagram, what does the symbol made of two long lines and two short lines with a positve and a negative sign at each end represent?

a.

an electrical conductot

b.

a closed switch

c.

a source of electrical energy

d.

an electrical resistor

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?

A-4.60 μc charge is moving at a constant speed of 6.80×105 m/s in the +x−direction relative to a reference frame. at the instant when the point charge is at the origin, what is the magnetic-field vector it produces at the following points.

Un jugador de beisbol batea un foul recto en el aire.la pelota deja el bate con una rapidez de 120 km/h. en ausencia de resistencia del aire. ? cual sera la rapidez de la pelota cuando la atrape el catcher