Advertisements
Advertisements
प्रश्न
What would be the effect on the resistance of a metal wire of:
increasing its diameter?
Advertisements
उत्तर
The resistance of a conductor is inversely proportional to its area of cross-section, i.e. R α 1 / A. So on increasing its diameter, its resistance will decrease.
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:
What is meant by conductors and insulators? Give two examples of conductors and two of insulators.
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.
Name the electrical property of a material whose symbol is "omega".
What do you understand by the "resistivity" of a substance?
A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 Ω. Calculate the resistivity of its material?
Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is 1.7 × 10−8 Ω m.
How does the resistance of a conductor depend on:
temperature of the conductor?
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.
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?
Materials which allow larger currents to flow through them are called:
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?

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 ______.
