Page 63 - iScience K to 12 Curriculum Series

U
There are ways by which electric charges Examples: N
flow. The two processes by which electric I
charges flow are called electron flow and 1. 100 Coulombs of charge flow past a point T
conventional flow. Electron flow occurs in 20 seconds. What is the current in
when charges flow from negative to positive ampere?
charge. On the other hand, conventional flow 1
happens when charges flow from positive Given:
charge to negative charge. Q = 100 Coulomb
t = 20 seconds 2
Current
Find: I 3
Electric current exists whenever an electric
charge is being transferred from one point to Formula:
another in a given place. I = Q 4
t
Current is the net flow of charge at a Solution:
certain period of time. It is measured in terms 100C
of ampere, a unit named after André-Marie I = 20 s
Ampère. An ammeter measures the amount C
of current that flows in an electric circuit. I = 5 s
Or 5 A

2. A charge of 0.8 passes through a wire in 4
seconds. What is the current in it?

Given:
Q = 0.8C
t = 4 seconds

Find: I

Formula:
Q
I =
Andre-Marie Ampere and the Ammeter t
Solution:
An electric circuit is composed of a wire, I = 0.8 C
bulb, and switch. Electric current can be 4 s
calculated using the equation: I = 0.2 C
s
Q Or 0.2 A
I = t

where:
I = current in coulomb/sec or Ampere
Q = number of charges transported in
Coulomb
t = time taken to transport the charges
in seconds

50 iScience 8: K to 12 Curriculum Series iScience 8: K to 12 Curriculum Series 51