Example The current in a mobile phone circuit is 2.00 mA. How many electrons moved through part of the circuit in a one minute interval? Solution Think about how to solve the problem. What do you know? Visualize the physical situation Draw an annotated diagram showing the known and unknown physical quantities. N Suppose that a current consists of charge carriers (electrons) each q v with a charge of magnitude drifting along at an average speed V L = v dt within a cylinder of volume with length and cross-sectional A. area v Fig. 3. Electrons drifting at speed through a metal cylinder A dt. of cross-sectional area in the time interval
Example The current in a mobile phone circuit is 2.00 mA. How many electrons moved through part of the circuit in a one minute interval? Solution Think about how to solve the problem. What do you know? Visualize the physical situation Draw an annotated diagram showing the known and unknown physical quantities. Suppose that a current consists of N charge carriers (electrons) each with a charge of magnitude q drifting along at an average speed v within a cylinder of volume V with length L = v dt and cross-sectional area A. Fig. 3. Electrons drifting at speed v through a metal cylinder of cross-sectional area A in the time interval dt.