Advertisements
Advertisements
प्रश्न
Why are alloys commonly used in electrical heating devices? Give reason.
Advertisements
उत्तर
Alloys are commonly used in electrical heating devices because
- They have a higher resistivity as compared to pure metals and has high melting point.
- They do not burn in oxygen i.e. they don't get oxidized readily at a higher temperature.
APPEARS IN
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:
List the factors on which the resistance of a conductor in the shape of a wire depends.
Which has less electrical resistance : a thin wire or a thick wire (of the same length and same material)?
Classify the following into good conductors, resistors and insulators:
Rubber, Mercury, Nichrome, Polythene, Aluminium, Wood, Manganin, Bakelite, Iron, Paper, Thermocol, Metal coin
What is meant by the "resistance of a conductor" ? Write the relation between resistance, potential difference and current.
Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity?
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.
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?
A cylindrical conductor of length l and uniform area of cross-section A has resistance R. Another conductor of length 2l and resistance R of the same material has an area of cross-section:
