Advertisements
Advertisements
Question
State Ohm’s law.
Solution
Ohm’s law states that electric potential difference across two points in an electrical circuit is directly proportional to the current passing through it. That is,
V~I
The proportionality constant is tne resistance (R) offered between the two points.
Hence, Ohm’s law is written as,
V = RI (or) V = IR
Where, V is the potential difference in volt (V), I is the current flow in ampere (A), R is the resistance in ohm (Ω)
APPEARS IN
RELATED QUESTIONS
How does the resistance of a metallic wire depend on its temperature? Explain with reason.
Calculate the potential difference between the two terminals of a battery if 100 joules of work is required to transfer 20 coulombs of charge from one terminal of the battery to the other.
Draw a graph of Potential difference (V) versus Current (I) for an ohmic resistor. How can you find the resistance of the resistor from this graph?
From the following observations taken while determining the resistance of a conductor, draw the current-voltage graph and calculate the resistance of conductor. Is the conductor ohmic?
Ammeter reading I (in ampere) | Voltmeter reading V (in volt) |
0.2 | 0.4 |
0.3 | 0.6 |
0.5 | 1.0 |
0.8 | 1.6 |
1.5 | 3.0 |
Three resistors are connected to a 6 V battery as shown in the figure given below:
Calculate:
(i) the equivalent resistance of the circuit.
(ii) total current in the circuit.
(iii) potential difference across the 7.2 Ω resistor.
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.
Assertion (A): Charges flow from higher potential to lower potential.
Reason (R): Current flows mainly due to the flow of electrons.
What is the measure of the work done on the unit positive charge to bring it to that point against all electrical forces?
Two charged spherical conductors of radius R1 and R2 are connected by a wire. Then the ratio of surface charge densities of the spheres (σ1/σ2 ) is ______