Advertisements
Advertisements
प्रश्न
Temperature dependence of resistivity ρ(T) of semiconductors, insulators and metals is significantly based on the following factors:
- number of charge carriers can change with temperature T.
- time interval between two successive collisions can depend on T.
- length of material can be a function of T.
- mass of carriers is a function of T.
पर्याय
a and b
b and c
c and d
a and c
उत्तर
a and b
Explanation:
Resistivity is the intrinsic property of the substance. For a metallic conductor, resistivity is given by
`ρ = m/("ne"^2τ)`
Where n is the number of charge carriers per unit volume (number density) which can charge with temperature T and τ is relaxation time (time interval between two successive collisions) which decreases with the increase of temperature `(T oo 1/τ)`.
APPEARS IN
संबंधित प्रश्न
A silver wire has a resistance of 2.1 Ω at 27.5°C, and a resistance of 2.7 Ω at 100°C. Determine the temperature coefficient of resistivity of silver.
The order of coloured rings in a carbon resistor is red, yellow, blue and silver. The resistance of the
carbon resistor is:
a) 24 x 106 Ω ± 5%
b) 24 x 106 Ω ± 10%
c) 34 x 104 Ω ± 10%
d) 26 x 104 Ω ± 5%
Sometimes it is said that "heat is developed" in a resistance when there is an electric current in it. Recall that heat is defined as the energy being transferred due to temperature difference. Is the statement in quotes technically correct?
Is inversion temperature always double the neutral temperature? Does the unit of temperature have an effect in deciding this question?
As temperature increases, the viscosity of liquids decreases considerably. Will this decrease the resistance of an electrolyte as the temperature increases?
The 2.0 Ω resistor shown in the figure is dipped into a calorimeter containing water. The heat capacity of the calorimeter together with water is 2000 J K−1. (a) If the circuit is active for 15 minutes, what would be the rise in the temperature of the water? (b) Suppose the 6.0 Ω resistor gets burnt. What would be the rise in the temperature of the water in the next 15 minutes?
The figure shows an electrolyte of AgCl through which a current is passed. It is observed that 2.68 g of silver is deposited in 10 minutes on the cathode. Find the heat developed in the 20 Ω resistor during this period. Atomic weight of silver is 107.9 g/mol−1.
A metallic wire has a resistance of 3.0 Ω at 0°C and 4.8 Ω at 150°C. Find the temperature coefficient of resistance of its material.
