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प्रश्न
Fill in the following blanks with suitable words:
Copper is a good .......... Plastic is an ..........
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उत्तर
Copper is a good conductor. Plastic is an insulator
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संबंधित प्रश्न
On what factors does the resistance of a conductor depend?
What is (a) the highest, (b) the lowest total resistance that can be secured by combinations of four coils of resistance 4 Ω, 8 Ω, 12 Ω, 24 Ω?
Why are copper and aluminium wires usually employed for electricity transmission?
List the factors on which the resistance of a conductor in the shape of a wire depends.
Why are alloys commonly used in electrical heating devices? Give reason.
What is meant by conductors and insulators? Give two examples of conductors and two of insulators.
What is meant by the "resistance of a conductor" ? Write the relation between resistance, potential difference and current.
What happens to the resistance as the conductor is made thicker?
What will be the resistance of a metal wire of length 2 metres and area of cross-section 1.55 × 10−6 m2 if the resistivity of the metal be 2.8 × 10−8 Ω m?
What would be the effect on the resistance of a metal wire of:
increasing its length?
How does the resistance of a wire change when:
its material is changed to one whose resistivity is three times?
The figure blow shows a variable resistor in a dimmer switch.
How would you turn the switch to make the lights: (a) brighter, and (b) dimmer? Explain your answer.
The element used almost exclusively for filaments of incandescent lamps:
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.
