Referring to figure (a) and (b) : (1) reading of spring balance in (a) is 8 g and - Physics - Electric Charges And Fields

Question

Referring to figure (a) and (b) : 
 (1) reading of spring balance in (a) is 8 g and in (b) is also 8 g
(2) reading of spring balance in (a) is 8 g and in (b), it is less
than 8 g (3) reading in (a) is less than 8 g and in (b), it is 8 g
(4) reading in both (a) and (b) is less than 8 g

Peter Fernandes · Accepted Answer

Consider that the two masses
m1 and m2 are hanging from the two ends
of a cord running over a smooth fixed pulley
Considering the masses are
unequal:
m1g-T=m1aT-m2g=m2aAddinga=m1-m2m1+m2gT=2m1m2gm1+m2
Then the tension on the string connecting the pulley and balance is
twice the tension on the string connecting the two bodies
Thus the tension in the string connecting the pulley and balance
is
T1=4m1m2gm1+m2

Hence the reading on the balances would be
Case (a)
4628g=6g
Case (b)
4448g=8g
Thus option (3) is correct

Referring to figure (a) and (b) : (1) reading of spring balance in (a) is 8 g and in (b) is also 8 g (2) reading of spring balance in (a) is 8 g and in (b), it is less than 8 g (3) reading in (a) is less than 8 g and in (b), it is 8 g (4) reading in both (a) and (b) is less than 8 g