Question

Assertion :The electrical resistance of a column of 0.05 M NaOH solution of diameter 1 cm and length 50 cm is $5.55\times {10}^3$ ohm.
Reason: Its resistivity is equal to 76.234 ohm-cm.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Given,

$0.05M$ $NaOH$ solution

Diameter $=1cm\Rightarrow$ Radius $=0.5cm$

length $=50cm$

$R=5.5\times {10}^3\Omega$

$\therefore$ Area $=\pi r^2=3.14\times (0.5{)}^{2}c{m}^2$

$=0.785c{m}^2$

Now,

Resistance $\left(R\right)=P\frac{l}{A}$

$\therefore P=\frac{R\times A}{l}=\frac{5.55\times {10}^3\times 0.785}{50cm}$

$=87.135$

Assertion is right but reason is not correct

explanation for Assertion.