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How does the resistance of a wire depend on its radius? Explain your answer.
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Resistance of a wire is inversely proportional to the area of cross-section of the wire.
`R ∝ 1/"r"^2 or R prop 1/"a" or R ∝ 1/"ЁЭЬЛЁЭСЯ"^2`
where 'a' is the area of cross-section and r is the radius of wire and R is the resistance. In other words thick wire offers less resistance and thin wire offers more resistance. In thick conductor electrons suffer less collisions.
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Name three factors on which resistance of a given wire depends and state how is it affected by the factors stated by you.
The effective resistance of three resistors connected in series is lesser than the lowest of the individual resistances.
What happens to the resistance, as the conductor is made thicker?
______ is the only non-metal that is a good conductor of electricity.
If the area of cross-section of the conductor is doubled its resistance gets ______.
Three resistors are connected in series with a cell. If the current in each resistor is 1.5A, then the current through the cell will be ______.
The process of conduction of electric current through the solution is called ______.
Match the following:
| Column I | Column II | ||
| 1. | Resistor | a. | Galvanometer |
| 2. | Connecting wire | b. | Voltmeter |
| 3. | Current in an electric circuit | c. | Copper |
| 4. | Potential difference | d. | Constantan |
Define the following:
Fixed resistor
Observe the given circuit diagram and answer the questions that follow:
- Calculate the resistance of the circuit when the key K completes the circuit.
- Calculate the current through 3Ω resistance when the circuit is complete.
