What is electrical resistivity of a material? What is its unit?Describe an experiment to study the factors on which theresistance of conducting wire depends.

Electrical resistivity of a material is a measure of the material's ability to oppose the flow of electric current. This means, the higher the resistivity, the more the material resists the flow of electricity. It is a property intrinsic to the material and is usually denoted by the Greek letter ρ (rho).

The unit of electrical resistivity in the International System of Units (SI) is the ohm meter (Ω⋅m).

To study the factors on which the resistance of a conducting wire depends, you can perform the following experiment:

Materials needed: A battery, a switch, an ammeter, a voltmeter, a rheostat (variable resistor), a meter stick, a micrometer screw gauge, and wires of different materials and lengths.

Steps:

1. Set up a simple circuit with the battery, switch, ammeter, voltmeter, and a wire. The ammeter is connected in series to measure the current flowing through the circuit, and the voltmeter is connected in parallel to measure the potential difference across the wire.
2. Close the switch and note the readings on the ammeter and voltmeter.
3. Use Ohm's law (V = IR) to calculate the resistance of the wire, where V is the potential difference, I is the current, and R is the resistance.
4. Repeat the experiment with wires of different lengths and materials. Keep the cross-sectional area of the wire constant.
5. Also, repeat the experiment with wires of the same material and length but different cross-sectional areas.
6. Record all your observations.

From this experiment, you will observe that the resistance of the wire depends on its length, cross-sectional area, and the material it is made of. The resistance is directly proportional to the length and inversely proportional to the cross-sectional area. Different materials also have different resistivities, affecting their resistance.