To solve this problem we will apply the concepts related to the Magnetic Force, this is given by the product between the current, the body length, the magnetic field and the angle between the force and the magnetic field, mathematically that is,
Here,
I = Current
L = Length
B = Magnetic Field
= Angle between Force and Magnetic Field
But 
Rearranging to find the Magnetic Field,
Here the force per unit length,
Replacing with our values,
Therefore the magnitude of the magnetic field in the region through which the current passes is 0.0078T
Answer:
Option A
Explanation:
This can be explained based on the conservation of energy.
The total mechanical energy of the system remain constant in the absence of any external force. Also, the total mechanical energy of the system is the sum of the potential energy and the kinetic energy associated with the system.
In case of two stones thrown from a cliff one vertically downwards the other vertically upwards, the overall gravitational potential energy remain same for the two stones as the displacement of the stones is same.
Therefore the kinetic energy and hence the speed of the two stones should also be same in order for the mechanical energy to remain conserved.
The answer is true I think
