Tiêu đề Practical Kida (2).pdf ✅

PracticalKida.com Practical No:- 04 Determination of specific resistance of given wire To determine the radius and hence area of the given wire: Dimensi on MS R (cm) CS D CS R (cm ) TR (cm ) CR (cm ) Average reading (cm) Diameter (d) of wire (cm) Area of cross-se ction (cm2) Diameter (d) of wire 1.5 35 0.03 5 1.53 5 4.86 6 1.533 0.488 0.751 Diameter (d) of wire 1.6 28 0.02 8 1.62 8 5.14 7 1.626 0.517 0.838 Diameter (d) of wire 1.5 37 0.03 7 1.53 7 4.87 2 1.535 0.489 0.754 Observation Table:
PracticalKida.com Observation Table: ● Least count of ammeter: 0.01 A ● Range of ammeter: 0-5 A ● Least count of voltmeter: 0.01 V ● Range of voltmeter: 0-5 V Observation Table: Obs . No. Length of wire (L) in cm Current (I) in ampere Potential difference (V) in volt Resistance of Wire R = V/I Ω Specific resistance ρ = Ra/L Ω-cm 1 20 0.25 1.00 4.00 0.80 2 30 0.20 1.20 6.00 0.80 3 40 0.18 1.40 7.78 0.78 4 50 0.16 1.60 10.00 0.80 5 60 0.15 1.80 12.00 0.80
PracticalKida.com 6 70 0.14 2.00 14.29 0.81 7 80 0.13 2.20 16.92 0.85 8 90 0.12 2.40 20.00 0.89 Mean Resistance: (4.00 + 6.00 + 7.78 + ...) / 8 = 9.85 Ω Specific resistance of the material of given wire by experiment: (0.80 + 0.80 + 0.78 + ...) / 8 = 0.80 Ω-cm Specific resistance of the material of given wire by graph: If the slope of the graph is 0.01 Ω/cm and the cross-sectional area (a) is 0.75 cm2, then ρ = 0.01 Ω/cm × 0.75 cm2 = 0.0075 Ω-cm. Conclusion: The specific resistance of the given wire was determined experimentally and graphically. The experimental and graphical values were found to be consistent, confirming the relationship between resistance, length, and cross-sectional area of a conductor as described by Ohm's law.
PracticalKida.com Practical Related Questions 1. State the factors on which specific resistance of the wire depends in your experiment. Answer: Material of the wire: Different materials have different intrinsic specific resistances. Temperature: The specific resistance of a material generally increases with temperature. Impurities: The presence of impurities in the material can affect its specific resistance. Annealing: The process of annealing (heating and cooling) can alter the structure of the material and affect its specific resistance. 2. For two wires of same length and different radii, does the resistance of wire change? Give reasons. Answer: Yes, the resistance of a wire changes with its radius. This can be explained by the formula for the resistance of a conductor: R = ρ * L / A