Question

Question 9 please
I uploaded the picture such a way so that you can get many questions to solve. BUT PLEASE QUESTION 9????

Answer 1

Answer:

xidatiom and resulation path

Answer 2

$\Huge{\underline{\underline{\blue{\mathfrak{Question :}}}}}$

A wire is of 1 m long, 0.2 mm diameter has resistance of 200 Ω . Find Resistivity of the wire.

$\rule{200}{2}$

$\Huge{\underline{\underline{\blue{\mathfrak{Answer :}}}}}$

....Given.....

• Length of wire = 1 m
• Diameter of wire = 0.2 mm
• Resistance (R) = 200 Ω

We have formula :-

$\LARGE \implies {\boxed{\boxed{\tt{R \: = \: \rho (\frac{L}{A})}}}}$

As we have to find Resistivity,

$\Large{\boxed{\sf{\rho \: = \: R \frac{A}{L}}}}$

$\rule{100}{2}$

Convert mm to m by multiplying it by 10^(-3)

→ Diameter = 0.2 × 10^(-3)

→ Diameter = 2 × 10^(-4) m

As,

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2*Radius = Diameter

Radius = Diameter/2

Radius = [2 × 10^(-4)]/2

Radius = 10 × 10^(-4)

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Now, Find Area of Wire ,

As,

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Area of circle = πr²

→ Area = 3.14 × [(10)^(-4)]²

→ Area = 3.14 × 10^(-8)

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$\Large{\boxed{\sf{Area \: = \: 3.14 \: \times \: 10^{-8} \: m^2}}}$

$\rule{200}{2}$

Now, put values in formula

$\Large \leadsto {\bf{\rho \: = \: \frac{(200) \: \times \: 3.14 \: \times \: 10^{-8}}{1}}}$

$\Large \leadsto {\bf{\rho \: = \: 628 \: \times \: 10^{-8}}}$

$\Large \implies {\boxed{\red{\sf{\rho \: = \: 6.28 \: \times \: 10^{-10}} \: \Omega m}}}$