Resistance

    Resistance is the opposition to the flow of electric current in a circuit. It is measured in ohms (Ω).

• Analogy: Think of resistance like a narrow pipe restricting the flow of water. The narrower the pipe, the higher the resistance.
• Factors affecting resistance:
• Material: Different materials have different resistivities (ability to resist current). Conductors have low resistivity, and insulators have high resistivity.
• Length: Longer wires have higher resistance.
• Cross-sectional area: Thicker wires have lower resistance.
• Temperature: In most conductors, resistance increases with temperature.

Ohm's Law:

• Formula: V = IR
• V = Voltage (volts)
• I = Current (amperes)
• R = Resistance (ohms)
• Importance: Ohm's Law is a fundamental relationship in electronics, used to calculate voltage, current, or resistance in a circuit.

Types of Resistors:

• Fixed resistors: Have a specific resistance value.
• Variable Resistors: Resistance can be adjusted (potentiometers, rheostats).

Study Notes

• Resistance limits the amount of current that can flow in a circuit.
• Resistors are used to control current and voltage levels in electronic devices.
• Power is dissipated in resistors, which causes them to heat up.

Short Notes

• Resistance: Opposition to current flow.
• Unit: Ohms (Ω).
• Factors: Material, length, area, temperature.
• Ohm's Law: V = IR.

Here are give you some multiple-choice questions for practicing. Practice well and get more marks for your exam.

Time's Up

score:

Total Questions:

Attempt:

Correct:

Wrong:

Percentage: