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
The values of current (I) flowing through a given resistor of resistance (R), for the corresponding values of potential difference (V) across the resistor are as given below:
| V (volts) | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 4.0 | 5.0 |
| I (amperes) | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.6 | 0.8 | 1.0 |
Plot a graph between current (I) and potential difference (V) and determine the resistance (R) of the resistor.
You have three resistors of values 2Ω, 3Ω and 5Ω. How will you join them so that the total resistance is more than 7Ω?
1) Draw a diagram for the arrangement
2) Calculate the equivalent resistance.
What is meant by saying that the electric potential at a point is 1 volt?
If a potential difference of 10 V causes a current of 2 A to flow for 1 minute, how much energy is transferred?
Keeping the potential difference constant, the resistance of a circuit is doubled. The current will become:
Write proper word from the following group of words in the blank.
(magnetism, 4.5V, 3.0V, gravitational attraction, potential difference, potential, higher, lower, 0V)
Water in the waterfall flows from a higher level to the lower level because of ______.
Suppose there are three resistors A, B, and C having resistances r1, r2, and r3 respectively. If R represents their equivalent resistance, establish the following relation `1/"R" = 1/"r"_1 + 1/"r"_2 + 1/"r"_3`, when joined in parallel.
State Ohm’s law.
A negative charge will move from ______ to ______ potential.
Two charged spherical conductors of radius R1 and R2 are connected by a wire. Then the ratio of surface charge densities of the spheres `(σ_1//σ_2 )` is ______.
