Advertisements
Advertisements
Question
- Name and state the law which relates the potential difference and current in a conductor.
- What is the necessary condition for a conductor to obey the law named above in part (a) ?
Advertisements
Solution
- The law is called Ohm's law. It states that the current flowing through the conductor is directly proportional to the potential difference across the ends of the conductor, given that the temperature remains constant.
- The temperature should remain constant.
APPEARS IN
RELATED QUESTIONS
If the potential difference across the ends of a conductor is 220 V and the resistance of the conductor is 44 Ω (ohm), then the current flowing through is _________.
- 0.2 A
- 0.5 A
- 2 A
- 5 A
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
A low voltage supply from which one needs high currents must have very low internal resistance. Why?
A wire of resistance 3 ohm and length 10 cm is stretched to length 30 cm. Assuming that it has a uniform cross section, what will be its new resistance?
In the circuit shown below in Fig, calculate the value of x if the equivalent resistance between A and B is 4 Ω.

A wire has a length of 2.0 m and a resistance of 5.0 Ω. Find the electric field existing inside the wire if it carries a current of 10 A.
Tick(✓) the correct choice in the following:
Ohm's law is applicable to
Ohm's law deals with the relationship between ______
The circuit depicted in the figure is employed for studying Ohm’s Law. Instead of using a standard resistor, a student opts for a glass tube filled with mercury (tube 1), connected to the circuit through two electrodes, E1 and E2. He records the readings of the ammeter and voltmeter, thereby calculating the resistance. The student repeats the experiment by substituting tube 1 with tube 2, where the same amount of mercury fills tube 2.

Neglecting internal resistance of the cell use (> or < or =) to compare:
- the resistance in both the cases.
- the voltmeter readings in both the cases.
- the specific resistance in both the cases.
