Question

For the arrangement in figure, the tension in the string to prevent it from sliding down is:

• A. 6 N
• B. 6.4 N
• C. 0.4 N
• D. zero

Answer 1

The correct option is D zero

$mgsin\theta$ is acting downward and is equal to $=1\times 10\times sin{37}^o=10\times \frac{3}{5}=6N$
the maximum force of friction $=\mu mgcos\theta$
$=0.8\times 1\times 10cos{37}^o$
$=0.8\times 10\times \frac{4}{5}=\frac{32}{5}\approx 6.4N$
The full force of friction is not used. Therefore even without the string, the body will remain at rest hence tension is zero.