Explanation
Temperature coefficient of a semiconductor is negative.
The reciprocal of resistance is called conductance.
According to ohm’s law V= IR.
With increase in temperature the ions of the conductor vibrate with greater amplitude and the collision between ions and electrons becomes more frequent. So, resistance of metal increases with increasing temperature.
The free electrons in a conductor move randomly with speed of order 105 m/s at room temperature. Since the motion of the electrons is random there is no net charge flow in any direction.
Supercurrent always flows on the surface of super conductors.
In semiconductor, resistance have negative temperature coefficient . So, resistance will decrease with increase in temperature.
Velocity of electron increases with rise in temperature. Hence, relaxation time and drift velocity will decrease.
Number of electrons per unit volume of a conductor is very large. So large current is obtained in conductor irrespective of their small drift speed.
For semiconductor , temperature coffecient of resistance is negative. Hence resistance increases on decreasing temperature.
These resistors are made of semiconductor whose resistance decreases with the increase in temperature. This implies that they have negative and high temperature cofficient of resistivity.
According to KVL , ∑ V =0
It states that algebraic sum of the potential differences in any loop including those associted emf’s and those of resesitive elements, must be equal to zero.
This law represents conservation of energy.
Resistance of ideal voltmeter is infinite
Green → 5 Gold → 5%
Black → 0
Violet → 107
R = 50 ×107 Ω ± 5%
= 500 ± 5% M Ω
i = ne Avd
4 = n × 1.6 × 10-19 × 2 × 10-6 × 2.1 × 10-4
n = 6 ×1028 m-3
Resistance of carbon decreases with the increase of temperature as the temperature coefficient of the carbon is negative.
Resistivity of alloy > Resistivity of metal
Resistivity of metal increases, when it is converted into an alloy.
Please disable the adBlock and continue. Thank you.