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प्रश्न
Why are copper and aluminium wires usually employed for electricity transmission?
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उत्तर
Copper and aluminium wires are often used to transmit electricity because:
- Copper and aluminium are good conductors of electricity also have low resistivity.
- Copper and aluminium have a low resistance, which makes them good conductors of electricity.
- Wires can be made easily from these.
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संबंधित प्रश्न
On what factors does the resistance of a conductor depend?
Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be:
A copper wire has diameter 0.5 mm and resistivity of 1.6 × 10−8Ω m. What will be the length of this wire to make its resistance 10 Ω? How much does the resistance change if the diameter is doubled?
List the factors on which the resistance of a conductor in the shape of a wire depends.
Fill in the following blanks with suitable words:
Copper is a good .......... Plastic is an ..........
What is meant by conductors and insulators? Give two examples of conductors and two of insulators.
What happens to the resistance as the conductor is made thinner?
What happens to the resistance as the conductor is made thicker?
Which has more resistance:
a thick piece of nichrome wire or a thin piece?
What do you understand by the "resistivity" of a substance?
How does the resistance of a conductor depend on:
area of cross-section of the conductor?
What would be the effect on the resistance of a metal wire of:
increasing its length?
What would be the effect on the resistance of a metal wire of:
increasing its temperature?
Calculate the area of cross-section of a wire if its length is 1.0 m, its resistance is 23 Ω and the resistivity of the material of the wire is 1.84 × 10−6 Ω m.
Write the relation between resistance and electrical resistivity of the material of a conductor in the shape of a cylinder of length `'l'` and area of cross-section `'A'` . Hence derive the S.I. unit of electrical resistivity.
How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistors R1, R2 and R3 in series connected to a battery of V volts?
Assertion: Conductors allow the current to flow through themselves.
Reason: They have free charge carriers.
How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistances in series connected to a battery?
The resistance of a wire of 0.01 cm radius is 10 Ω. If the resistivity of the wire is 50 × 10-8 Ω, find the length of this wire.
How will the resistance of a wire be affected if its
- length is doubled, and
- radius is also doubled ?
Give justification for your answer.
