Current electricity Flashcards
1
Q
resistivity in terms of tau
A
m/ne^2tau
2
Q
carbon coding resistors
A
BBROYGBVGW GSNoband Black 0 Brown1 Red2 Orange3 Yellow4 Green5 Blue6 Violet7 Gray8 White9 Gold 5% Silver10% Noband 20%
1st 2 bands: numbers
3rd band: exponent
4th band: tolerance level
3
Q
E in terms of current density
A
E = (rho)J
4
Q
Resistance across cube body diagonal
A
5R/6
5
Q
Resistance across cube face diagonal
A
3R/4
6
Q
Resistance across cube side
A
7R/12
7
Q
Determining internal resistance
A
(R+r)/R = l1/l2
l1 is without R in circuit
l2 is with R in circuit
8
Q
Heating time for resistances in series and parallel
A
t = t1+t2(series) 1/t = 1/t1 + 1/t2(parallel)
