Dimensions of a block are 1 cm × 1 cm × 100 cm. If specific resistance of its material is 3× 10-7 Ω m, then the resistance between the opposite rectangular faces is

Question

Dimensions of a block are 1 cm × 1 cm × 100 cm. If specific resistance of its material is 3× 10-7 Ω m, then the resistance between the opposite rectangular faces is (A) 3× 10-7 Ω m (B) 3× 10-9 Ω m, (C) 3× 10-5 Ω m, (D) 3× 10-3 Ω m,

Tardigrade Admin · Accepted Answer

Here length l=1 cm=10-2 m <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/9fd9df6151306e05d095c79b9aa29c81-.png" /> Area of cross-section, A = 1 cm×100 cm = 100 cm2 =10-2 m2 Resistance, R=ρ (ℓ/A)=3×10-7×(10-2/10-2) =3×10-7 Ω

Q. Dimensions of a block are $1 c m \times 1 c m \times 100 c m$ . If specific resistance of its material is $3 \times 1 0^{- 7} Ω m$ , then the resistance between the opposite rectangular faces is

$3 \times 1 0^{- 7} Ω m$

$3 \times 1 0^{- 9} Ω m$ ,

$3 \times 1 0^{- 5} Ω m$ ,

$3 \times 1 0^{- 3} Ω m$ ,

Here length $l = 1 c m = 1 0^{- 2} m$

Area of cross-section, $A = 1 c m \times 100 c m$
$= 100 c m^{2}$
$= 1 0^{- 2} m^{2}$
Resistance, $R = ρ \frac{ℓ}{A} = 3 \times 1 0^{- 7} \times \frac{1 0 ^{- 2}}{1 0 ^{- 2}}$
$= 3 \times 1 0^{- 7} Ω$

Q. Dimensions of a block are 1cm×1cm×100cm. If specific resistance of its material is 3×10−7Ωm, then the resistance between the opposite rectangular faces is

3×10−7Ωm

3×10−9Ωm,

3×10−5Ωm,

3×10−3Ωm,