The figure below shows lour situations in which positive and

The figure below shows lour situations in which positive and negative charges move horizontally and gives the rate at which each charge moves. Rank the situations according to the effective current through the regions, greatest first. (Use only the symbols > or =. tor example a>bsc>d.)

Solution

(A)

Charge is given by the area under current(I) vs time(t) curves

So,

Now, for curve (a)

Area = 1*2 = 2 units

for (b)

Area = 2*1= 2 units

for (c)

Area = 0.5*2*2 = 2 units

for (d)

0.5*1*2 - 0.5*1*2 = 0

So, ranking is :

(a = b = c) > d

(B)

For (a)

current = 7 C/s = 7 A

for (b)

current = 1 - 3 = -2 A

for (c)

current = 5 - 2 = 3 A

d)

current = -6 -1 = -7 A

So, the ranking is :

a > c > b > d