Advertisements
Advertisements
प्रश्न
Use the data in the Table given below to answer the following –
Which among iron and mercury is a better conductor?
Table give below Electrical resistivity of some substances at 20°C
Electrical resistivity of some substances at 20°C | ||
− | Material | Resistivity (Ω m) |
Conductors |
Silver | 1.60 × 10−8 |
Copper | 1.62 × 10−8 | |
Aluminium | 2.63 × 10−8 | |
Tungsten | 5.20 × 10−8 | |
Nickel | 6.84 × 10−8 | |
Iron | 10.0 × 10−8 | |
Chromium | 12.9 × 10−8 | |
Mercury | 94.0 × 10−8 | |
Manganese | 1.84 × 10−6 | |
Alloys |
Constantan (alloy of Cu and Ni) |
49 × 10−6 |
Manganin (alloy of Cu, Mn and Ni) |
44 × 10−6 | |
Nichrome (alloy of Ni, Cr, Mn and Fe) |
100 × 10−6 | |
Insulators | Glass | 1010 − 1014 |
Hard rubber | 1013 − 1016 | |
Ebonite | 1015 − 1017 | |
Diamond | 1012 − 1013 | |
Paper (dry) | 1012 |
उत्तर
Resistivity of iron = 10.0 × 10-8 Ω
Resistivity of mercury = 94.0 × 10-8 Ω
Resistivity of mercury is more than that of iron. This implies that iron is a better conductor than mercury.
APPEARS IN
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.
Distinguish between good conductors, resistors and insulators. Name two good conductors, two resistance and two insulators.
Classify the following into good conductors, resistors and insulators:
Rubber, Mercury, Nichrome, Polythene, Aluminium, Wood, Manganin, Bakelite, Iron, Paper, Thermocol, Metal coin
What happens to the resistance as the conductor is made thicker?
What do you understand by the "resistivity" of a substance?
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?
How does the resistance of a conductor depend on:
length of the conductor?
How does the resistance of a conductor depend on:
temperature of the conductor?
What would be the effect on the resistance of a metal wire of:
increasing its diameter?
What would be the effect on the resistance of a metal wire of:
increasing its temperature?
How does the resistance of a wire change when:
its material is changed to one whose resistivity is three times?
Materials which allow larger currents to flow through them are called:
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?
Plastic insulation surrounds a wire having diameter d and length l as shown above. A decrease in the resistance of the wire would be produced by an increase in the ______.