Current electricity

Question 1

resistivity in terms of tau

Answer 1

m/ne^2tau

Question 2

carbon coding resistors

Answer 2

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

Question 3

E in terms of current density

Answer 3

E = (rho)J

Question 4

Resistance across cube body diagonal

Answer 4

5R/6

Question 5

Resistance across cube face diagonal

Answer 5

3R/4

Question 6

Resistance across cube side

Answer 6

7R/12

Question 7

Determining internal resistance

Answer 7

(R+r)/R = l1/l2

l1 is without R in circuit
l2 is with R in circuit

Question 8

Heating time for resistances in series and parallel

Answer 8

t = t1+t2(series)
1/t = 1/t1 + 1/t2(parallel)