Question

a cylinder of materia l 10m long has a cross section of 2cm^ if its resistance along the length be 20ohm what will be its resistivity .....someone answer fast plz

Answer 1

Given

• Length = 10m
• Area of cross section = 2cm²
• Resistance = 20Ω

Find out

• Find out resistivity

Solution

★ Resistivity ★ = The resistivity of conductor is defined as the resistance offered by a conductor having unit length and unit area of cross section.

→ Area of cross section = 2cm²

★ 1cm² = 1/100 × 100

→ A = 2/100 × 100

→ A = 0.0002 m²

As we know that

→ ρ = R × A/l

→ ρ = 20 × 0.0002/10

→ ρ = 2 × 0.0002

→ ρ = 0.0004 Ω - m

where

• ρ → resistivity
• R → Resistance
• A → Area of cross section
• l → length

Answer 2

Answer:

$\small{\bf{\underline{\pink{Given :}}}}$

Length of cylinder, 1 = 10 cm = 10 ×${10}^{-4}$m

Area of Cross Section, A = 2 cm² =2× ${10}^{-4}$m²

_____________

Resistance, $\boxed{\red{R = 20 ohm}}$

Resistance, $\boxed{\red{P = ? }}$

Then using the realation,

$\Large p = \frac{R × A}{1}$

$\Large = \frac{</p><p></p><p>[tex]\boxed{\green{4 × 10-⁴}}$