Answer:
The magnetic field along x axis is

The magnetic field along y axis is zero.
The magnetic field along z axis is

Explanation:
Given that,
Length of the current element 
Current in y direction = 5.40 A
Point P located at 
The distance is


We need to calculate the magnetic field
Using Biot-savart law

Put the value into the formula

We need to calculate the value of 



Put the value into the formula of magnetic field


Hence, The magnetic field along x axis is

The magnetic field along y axis is zero.
The magnetic field along z axis is

Answer:
Zero
Explanation:
here, the inductive reactance and the capacitive reactance is same, so this is the condition for resonance.
In the condition for resonance,
the circuit and the voltage in the circuit is in the same phase and the impedance of the circuit is minimum which is equal to the resistance of the circuit.
The phase angle is given by

Ф = 0
Answer:
Part a)

Part b)
Ball thrown downwards =
Ball thrown upwards =
Part c)

Explanation:
Part a)
Since both the balls are projected with same speed in opposite directions
So here the time difference is the time for which the ball projected upward will move up and come back at the same point of projection
Afterwards the motion will be same as the first ball which is projected downwards
so here the time difference is given as



Part b)
Since the displacement in y direction for two balls is same as well as the the initial speed is also same so final speed is also same for both the balls
so it is given as




Part c)
Relative speed of two balls is given as


now the distance between two balls in 0.8 s is given as



So that we do not contaminate it with microorganisms or garbage or other human stuff.