O Levels Physics Tuition Lesson March Update
March has been an electrifying month as we dive into the wonders of electric current, its uses and safety issues.
Here are the topics covered:
Current of Electricity
Here are some important points to take note:
Electric current is defined as rate of flow of electric charge passing through a point
I = Q/t (or I am a cutie!)
Current in series circuit is the same, current in parallel must equal to total current before and after branching out (aka kirchoff's first law)
Potential difference is defined as the amount of work done to drive a unit charge (in coulombs) across a conductor
Potential difference in series circuit is equal to sum of potential difference of individual components. Potential difference in parallel circuit is the same for all components.
Electromotive Force (EMF) is defined as the amount of work done to drive a unit charge (in coulombs) across the entire circuit. EMF is NOT a force, EMF depends on the power source and not the circuit.
Ohm's Law - a change in current through a conductor is directly proportional to the change in potential difference across a conductor
A conductor obeying ohm's law is ohmic
Non-ohmic conductors include thermistors, diodes, and filament lambs
Potentials are points, potential difference is the difference between points
It is important to know all the current-potential difference graphs for all the different types of conductors
1 unit of electricity is known as 1 kWh. It is used to calculate the cost of using an electrical appliance
The key to doing well for these topics is to keep practicing. Take the usual number of questions you do for other topics and triple that number. That is the benchmark in order to do well in electricity. The reason being is that there are so many rules and fomulae to keep track that you need to keep working on the questions until you can remember them by heart.
So keep trying and don't lose heart! The more practice you have, the closer you are to mastering it!
If you need help in this topic, we are here for you! Whatsapp us at 8749 8157!