FreeNotes
Resistances in Series Connection When resistors are connected end-to-end in a single path for the flow of current, they are said to be in series. In this type of connection, the current remains the same through all the resistors, but the voltage divides among them. Characteristics of Series Resistance Connection Same Current: The same current … Read more
Definition of Resistance Resistance (RRR) is the opposition offered by a material to the flow of electric current. It determines how much a conductor resists the movement of free electrons when a voltage is applied. Mathematically, resistance is given by Ohm’s Law: R=V/I where: R = Resistance (Ohms, Ω) V = Voltage (Volts, V) I = … Read more
Analysis of IV Characteristic Graphs for Different Conductors The I-V characteristic graph represents the relationship between the current (I) and voltage (V) for different electrical components. The nature of this graph helps determine whether a material exhibits Ohmic or Non-Ohmic behavior. 1. Metallic Conductor (Ohmic Behavior) Graph Shape: A straight line passing through the origin. … Read more
Ohm’s Law Ohm’s Law states that the current (III) flowing through a conductor is directly proportional to the voltage (VVV) across it, provided the temperature and other physical conditions remain constant. Mathematically, it is expressed as: V=IR where: V = Voltage (Volts, V) I = Current (Amperes, A) R = Resistance (Ohms, Ω\OmegaΩ) Limitations of Ohm’s … Read more
Difference Between EMF and Potential Difference Aspect Electromotive Force (EMF) Potential Difference (PD) Definition The total energy supplied by a source per unit charge to drive the charge around a complete circuit. The energy difference per unit charge between two points in a circuit. Symbol ε V Formula ε= W/Q V=W/Q Source Produced by a … Read more
Definition of Electric Current Electric current (III) is defined as the rate of flow of electric charge through a conductor or circuit. Mathematically, it is expressed as: I=Q/t where: I = current (in amperes, A Q = charge (in coulombs, C) t = time (in seconds, s) The SI unit of electric current is the … Read more
To show that Volt-Ampere (VA) is equal to Watt (W), let’s analyze the units step by step. Step 1: Define Power Electrical power (P) is given by: P=V×I where: V is the voltage in volts (V), I is the current in amperes (A). Step 2: Express SI Units The SI unit of voltage (V) is: 1 … Read more
The resistance of a filament is given by Ohm’s law: R=V2/P where: V=220V (same for both bulbs), P is the power rating. Step 1: Calculate the Resistance of Each Bulb For the 100 W bulb: R1=2202/100=48400/100=484 Ω For the 200 W bulb: R2=2202/200=48400/200=242 Ω Step 2: Relationship Between Resistance and Thickness The resistance of a wire is … Read more
If aluminum and copper wires of the same length have the same resistance, the aluminum wire must have a larger diameter than the copper wire. This is because the resistance of a wire is inversely proportional to its cross-sectional area, and since aluminum has a lower electrical conductivity than copper, it needs a larger cross-sectional … Read more