Answer:
12.56 A.
Explanation:
The magnetic field of a conductor carrying current is give as
H = I/2πr ............................... Equation 1
Where H = Magnetic Field, I = current, r = distance, and π = pie
Making I the subject of the equation,
I = 2πrH............... Equation 2
Given: H = 1 T, r = 2 m.
Constant: π = 3.14
Substitute into equation 2
I = 2×3.14×2×1
I = 12.56 A.
Hence, the magnetic field = 12.56 A.
The magnetic force on a current-carrying wire due to a magnetic field is given by

where
I is the current
L the wire length
B the magnetic field strength
In our problem, L=1.0 m,

and

, so we can re-arrange the formula to find the current in the wire:
To solve this problem it is necessary to apply the concepts related to the capacitance in the disks, the difference of the potential and the load in the disc.
The capacitance can be expressed in terms of the Area, the permeability constant and the diameter:

Where,
= Permeability constant
A = Cross-sectional Area
d = Diameter
Potential difference between the two disks,
V = Ed
Where,
E = Electric field
d = diameter
Q = Charge on the disk equal to 
Through the value found and the expression given for capacitance and potential, we can define the electric charge as





Re-arranging the equation to find the diameter of the disks, the equation will be:

Replacing,


Therefore the diameter of the disks is 0.03m
Both options 5 and 6
Explanation:
Let us consider option 5,
In option 5 body is moving up with initial velocity lower than that of final velocity which gets accelerated. Therefore the acceleration is positive in this case.
Let us consider option 6,
In option 6 body is moving down with initial velocity lower than that of final velocity which gets accelerated. Therefore the acceleration is positive in this case.