Electronics - Lecture 1 PDF

(A) Electric Current : the current is the rate at which charge flows through this surface  ΔQ 1C I= 1A = Δt 1S...

(A) Electric Current : the current is the rate at which charge flows through this surface  ΔQ 1C I= 1A = Δt 1S Traditional Current Actual Current Conventional Traditional Microscopic Model of Current  numbers of carriers charge per carrier q A X drift velocity (E) Resistance J current density 3  J 3 3  3 5 5 4 Consider positive and negative charges moving horizontally through the four regions in figure. Rank the magnitudes of the current in these four regions from lowest to highest. ( Ia is the current in figure, Ib the current in figure, etc.. ▪ Id , Ia , Ic ,Ib ▪ Ia , Ic , Ib ,Id ▪ Ic , Ia , Id ,Ib ▪ Id , Ib , Ic ,Ia ▪ Ia , Ib , Ic ,Id ▪ None of these ================================================================================= The amount of charge that passes through the filament of a certain light blub in 2.00 s is 1.67 c. Find >> a) The average current in the light blub b) The number of electrons that pass through the filament in 5.00 s A cylindrical wire has a radius r and length L , if the both r and L doubled.. a) does the resistance of the wire increase? b) does the resistance of the wire decrease? c) does the resistance of the wire remain the same? =================================================================================== An electric heater is constructed by applying a potential difference of 120 V across a Nichrome wire that has a total resistance of 8Ω , find the current carried by the wireand the power rating of the heater