Advertisements
Advertisements
प्रश्न
How does the resistance of a metallic wire depend on its temperature? Explain with reason.
Advertisements
उत्तर १
With the increase in temperature of conductor, both the random motion of electrons and the amplitude of vibration of fixed positive ions increase. As a result, the number of collisions increases. Hence, the resistance of a conductor increases with the increase in its temperature. The resistance of filament of a bulb is more when it is glowing (i.e., when it is at a high temperature) as compared to when it is not glowing (i.e., when it is cold).
उत्तर २
The resistance of a metallic wire increases with increase in its temperature.
APPEARS IN
संबंधित प्रश्न
How much energy is given to each coulomb of charge passing through a 6 V battery?
The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below:
| I (amperes) | 0.5 | 1.0 | 2.0 | 3.0 | 4.0 |
| V (volts) | 1.6 | 3.4 | 6.7 | 10.2 | 13.2 |
Plot a graph between V and I and calculate the resistance of that resistor.
Keeping the potential difference constant, the resistance of a circuit is doubled. By how much does the current change?
A current of 200 mA flows through a 4 kΩ resistor. What is the p.d. across the resistor?
If the potential difference between the ends of a fixed resistor is halved, the electric power will become:
State the S.I. unit of electric potential.
Explain why potential difference is always less than the e.m.f. of a cell?
In the figure given below, A, B and C are three ammeters. The ammeter B reads 0.5A. (All the ammeters have negligible resistance.)
Calculate:
(i) the readings in the ammeters A and C.
(ii) the total resistance of the circuit.
Two bulbs are marked 100 W, 220 V and 60 W, 110 V. Calculate the ratio of their resistances.
Electric potential is a ____________.
