Advertisements
Advertisements
प्रश्न
- 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
उत्तर
- 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
संबंधित प्रश्न
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?
Write the formula of resistivity
The graph between V and I for a conductor is a straight line passing through the origin.
What should remain constant in a statement of this law?
A resistance of 40 ohms and one of 60 ohms are arranged in series across 220 volt supply. Find the heat in joules produced by this combination of resistances in half a minute.
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.
Show by a diagram how two resistors R1 and R2 are joined in parallel. Obtain an expression for the total resistance of the combination.
What are ohmic conductors? Give one exmaple. Draw a graph showing the current-voltage relationship for an ohmic conductor.
Why should an ammeter have low resistance?
A current of 3.2 mA flows through a conductor. If charge on an electron is −1.6 × 10-19 coulomb, find the number of electrons that will pass each second through the cross section of that conductor.
