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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
This indicates that the headlamps are connected in parallel. In a series circuit, if one bulb burns out, the entire circuit breaks, and both lamps stop working. In a parallel circuit, each lamp has an independent path to the power source. If one burns out, the other continues working normally. This is why automobile headlights … Read more
The earth acts as a conductor and is considered to be at zero potential. If a person touches a live wire while barefoot, a potential difference is created between the body and the earth, allowing current to flow through the body to the ground. This can result in severe electric shock or electrocution. To prevent … Read more
Water is a good conductor of electricity, especially when mixed with impurities. When hands are wet: The skin’s resistance decreases. A larger current can pass through the body if contact is made with a live wire. This can cause electric shock or serious injury. Dry hands have higher resistance, reducing the risk of electric shock. … 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
To solve this problem, we need to understand how the resistance behaves when wires are combined in series or parallel. Maximum Resistance: When resistances are combined in series, the total resistance is the sum of the individual resistances. For n wires, each with resistance R, the total resistance in series is: Rtotal series=nR So, the maximum … Read more
To arrange five resistances in a way that the total resistance is smaller than any given individual resistance, you should arrange them in parallel. Here’s how: Parallel connection: When resistors are connected in parallel, the total or equivalent resistance decreases. The formula for the total resistance Req of resistors connected in parallel is given by: … Read more
A bird sitting on a single wire is not electrocuted because both its feet are at the same potential, meaning no potential difference exists between them. Without a potential difference, current does not flow through the bird’s body. However, when the bird touches another wire (of a different potential), a potential difference is created between … Read more
Open switch: Infinite resistance. No current can flow. Closed switch: Zero resistance (ideally). It acts as a conductor, allowing current to flow freely. In an open switch, there is a physical gap, preventing charge flow. In a closed switch, the gap is bridged, allowing current to pass with negligible resistance. Related Questions: Can current flow … 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