Current Electricity and Electric Circuits

Rate of Charge Flow

Electric Potential Difference

Basic Symbols

• Electrons repel on another makes electric current.
• In the formula of calculating the rate of charge flow, I represents the current in amperes which is the base unit for current, Q represents the charge in coulombs - a electric unit represented by C, and t represents the time in seconds.
• The time must be converted to seconds in any of the calculation.
• The electric current-measuring device is called ammeter.
• DC, an abbreviation for direct current, in which the current flows in a single direction from the power supply through conductor to a load.
• AC is the abbreviation for alternating current, in which the flowing direction of the current periodically reverses with the help of electric and magnetic forces.
• Charge does not flow on its own, but a complete circuit allows the excess charge to be able to "see" a region of charge deficit.
• Power supply sets up an electric field. Electric charge in the electric field has a certain amount of electrical potential energy.
• The power supply increases the electrical potential energy of each coulomb of charge from a low to high value. The electrical potential energy of charge decreases as it flows though load.
• In the formula of electric potential difference, V stands for the electric potential difference, E stands for the energy required to increase the electric potential of a charge (Q).
• One volt (V) is the electric potential difference between two points if one Joule of work is required to move on coulomb of charge between the points.
• Formula E = VIt is used to calculate the amount of energy in joule; V represents the potential difference in volts, I is the current in amperes, and t is the time in seconds.
• Potential difference between any two points can be measured by using a voltmeter and the voltmeter must be placed parallel with the load.