Question

In a circuit, three pieces of wire labeled A, B and C are joined at a common point, D. If wire B carries 1.5 mA in a direction away from D and C carries current 1.3 mA toward D, what does wire A carry?
a. 0.2 mA toward D
b. 0.2 mA away from D
c. 2.8 mA toward D
d. 2.8 mA away from D
e. unable to determine

Answer 1

Answer:

correct option is a. 0.2 mA toward D

Explanation:

given data

B carries = 1.5 mA

C carries current  = 1.3 mA

solution

we take positive direction of current going away from the point D

and negative direction of current coming towards point D

so we use here kirchoff's current law   that is

iA + iB + iC = 0    ......................1

iA + 1.5 + (-1.3) = 0

iA = - 0.2 mA  

so that current in wire A is 0.2 mA towards point D

correct option is a. 0.2 mA toward D