Question

What is the reading of spring balance $D$ ?
(All the springs are ideal and identical)

• A. $\frac{mg}{4}$
• B. $2mg$
• C. $\frac{mg}{2}$
• D. $mg$

Answer 1

The correct option is D $mg$

The spring system can be converted to string system as shown

The FBDs of the system will be as shown


From the FBD we have,
$2T_1=mg$ and $T=2T_1$
$\Rightarrow T=mg$
Thus, the reading in the spring balance $D$ will be $T=mg$