Question

What is resistance and how it can be calculated?

Answer 1

Answer:

If you know the total current and the voltage across the whole circuit, you can find the total resistance using Ohm's Law: R = V / I. For example, a parallel circuit has a voltage of 9 volts and total current of 3 amps. The total resistance RT = 9 volts / 3 amps = 3 Ω.

Answer 2

Resistance :-

• The obstrucation to the motion of the electrons in a conductor is called Resistance of a conductor
• Resistance is directly proportional to the length of the conductor
• Resistance is inversely proportional to the area of a cross section of the conductor.
• $R = p \times \frac{l}{a}$
• Here p is specific resistance.

Resistivity :-

• The resistance of a conductor of unit length and unit area of cross section is called Specific resistance (or) Resistivity.
• $p = \frac{</em><em>R</em><em>a}{l}$
• S.I unit is Ohm - meter