Advertisements
Advertisements
प्रश्न
State microscopic form of Ohm’s law.
Advertisements
उत्तर
Current density J at a point in a conductor is the amount of current flowing per unit area of the conductor around that point provided the area is held in a direction normal to the current.
J = `I/"A"`
Drift velocity, `"V"_"d" = "eE"/"m" tau`
I = `"neAV"_"d" = "neA" ("eA"/"m") tau ...["J" = "I"/"A"; sigma = ("ne"^2 tau)/"m"]`
`"I"/"A" = (("ne"^2tau)/"m")`E
J = σE
APPEARS IN
संबंधित प्रश्न
State Ohm’s law and draw a neat labelled circuit diagram containing a battery, a key, a voltmeter, an ammeter, a rheostat and an unknown resistance to verify it.
In the circuit shown in the figure, find the total resistance of the circuit and the current in the arm AD.
Consider the sacle of voltmeter shown in the diagram and answer the following questions :
(a) What is the least count of the voltmeter?
(b) What is the reading shown by the voltmeter ?
(c) If the voltmeter is connected across a resistor of 20 `Omega` how much current is flowing through the resistor?
What are ohmic conductors? Give one exmaple. Draw a graph showing the current-voltage relationship for an ohmic conductor.
Draw a neat diagram for the verification of Ohm’s law by voltmeter-ammeter method. By another diagram show the relation between p.d. and current.
A wire connected to a power supply of 230 V has power dissipation P1. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case, power dissipation is P2. The ratio of `"P"_2/"P"_1` is
Explain the equivalent resistance of a series resistor network.
The unit of specific resistance is ____________.
Calculate the total resistance of the circuit and find the total current in the circuit.
