Shortcut Methods
Electric Field and Potential
Shortcut Methods and Tricks:
- To quickly determine the direction of the electric field due to a point charge, remember that the field lines always point away from positive charges and toward negative charges.
- For a uniform electric field, the electric potential difference between two points is simply the product of the field strength and the distance between the points.
- Equipotential surfaces are always perpendicular to the direction of the electric field.
Capacitance
Shortcut Methods and Tricks:
- For a parallel-plate capacitor, the capacitance is directly proportional to the area of the plates and inversely proportional to the distance between them.
- The energy stored in a capacitor is proportional to both the capacitance and the square of the voltage across the capacitor.
- The time constant of a circuit with a capacitor and a resistor in series is equal to the product of the capacitance and the resistance.
- For a circuit with a capacitor and a resistor in parallel, the current flowing through the circuit is equal to the voltage divided by the total resistance, which includes both the capacitor and the resistor.
By utilizing these shortcut methods and tricks, it becomes easier and faster to solve numerical problems related to electric fields, potential, and capacitance.
