Question

At 25oC,the resistance of a given wire of length 1m and diameter 0.5m.m is 25ohm .what is the resistivity of the material of the wire at that temperature?

Answer 1

Answer:

Radius of the cross section of the wire(r) = 0.02 mm. = 0.002 cm. ∴ ρ = 2.62 × 10⁻⁶ Ω-cm. Hence, the Specific Resistance of the Resistivity of the wire is 2.62 × 10⁻⁶ Ω-cm.

Please mark it

Answer 2

Answer: 127.38 ohms-meter.

Given: Length of wire = 1m, diameter = 0.5mm and resistance is 25 ohms at 25°C.

To Find: Resistivity of the wire.

Step-by-step explanation:

Step 1: Resistance:

A conductor's ability to resist the flow of current through it is known as resistance.

The interaction between the applied voltage and the electric current flowing through it controls it.

Step 2: Resistance of a wire:

A wire's resistance is directly correlated with its length and inversely correlated with its cross-sectional area. Additionally, the conductor's material has an impact on resistance.

Ohm's law explains the fundamental behaviour of electrical circuits. Current, resistance, and voltage are all closely connected.

Resistance is a constant that is unaffected by current or voltage, according to Ohm's law.

If the length, cross-sectional area, and resistivity of the material are known, the resistance of a wire can be computed as follows:

$R=\rho\frac{L}{A}$

Where R is the resistance, $\rho$ is the resistivity of the wire, L is the length of the wire and A is the area of the cross-section of the wire.

The length of the wire – Longer the wire, the greater its resistance.

The greater the cross-sectional area, the less resistance it experiences.

The material's resistivity determines how resistant it is; the higher the resistivity, the more resistant it is.

Ohm's Law can be used to compute resistance if the voltage and current in a circuit are known.

$R=\frac{V}{i}$

Step 2:

R = 25 Ω

l = 1 m

d = 0.5 mm

r = 0.25 mm

d = $5\times10^{-4}$m

$A=\pi r^2$

$=3.14\times(0.25\times10^{-3})^2\\\\=0.1961\times10^{-6} m^2$

$R=\rho\frac{L}{A}\\\\\rho=\frac{RA}{L} =\frac{250\times 0.1961\times 10^{-6}}{1}=127.38$

Hence, correct answer is 127.38 ohms-meter.

For more questions please follow the links given below.

https://brainly.in/question/18471524

https://brainly.in/question/33528223

#SPJ2