Answer:
Magnitude of induced emf will be 87.5 volt
Direction of induced emf will be clockwise
Explanation:
We have given number of turns in the coil N = 50
Initial area 
Time is given dt = 0.1 sec
Magnetic field B = 1.25 T
From Faraday's law of electromagnetic induction
n

So magnitude of induced emf is 87.5 volt
Direction of induced emf will be clockwise
==> Take an Earth weight. Don't forget the unit.
==> Multiply it by 0.166 .
==> The product is its Moon weight. Don't forget the unit.
Example:
If I weigh 1,000 lbs on Earth.
Multiply 1,000 lbs by 0.166 .
I weigh 166 lbs on the Moon
Answer:
L = 1.545 m
Explanation:
Let the total length of the rod is L
now the torque must applied on the other end of the rod so that it will balance the torque due to weight of rock on other side of fulcrum
so we will have

so we have

F = 663 N

