Blog 1: Notes on Current Electricity

This device is used to measure the amount of electric current that runs through a circuit. The currents are measured in Amperes, so this device is called an Ammeter.

 A current is the flow of electric charges that passes through a conductor. Current can be measured by the formula:


I, represents the amount of current, measured in amperes. Q, represents the distance travels through the conductor. t, represents the time it took for the current to pass this distance in seconds. 

Example  
How much current flows through a hair dryer if 1400 C of charge pass through it in 3 minutes?

Given
Q = 1400C  t = 3 min  I = ?

Solution
t = 3 min (60 s / 1 min) = 180 s

I =  Q / t
  =  1400 C / 180 s
  =   7.78 C/s

Voltage is the electric potential difference which is represented by the formula:
V = E / Q
Where E represents the energy needed in joules and Q represents the charge in coulombs.

Voltage is measured by a voltmeter, which compares the potential difference before and after the load.