Answer:
It has moved a distance, S = 25.9 m
Explanation:
F = 40 v²........(1)
.........(2)
Equating (1) and (2)

Integrate both sides:

.
Answer:
E. Some charges in the region are positive, and some are negative.
Explanation:
Electric potential is given as;

where;
W is the work done in moving a charge between two points which have a difference in potential
Q is quantity of charge in the given region
If the electric potential at a given point in the region is zero, then sum of the charges in the given region must be equal to zero. For the charges to sum to zero, some will be positive while some will be negative,.
Therefore, the correct statement in the given options is "E"
E. Some charges in the region are positive, and some are negative.
Answer:
8 x 10⁻⁷ x I / r
Explanation:
Two parallel long wires are carrying current I . Let the direction be towards the right in the farthest and towards the left in the nearest. Magnetic field due to current I at a distance d is given by the expression
B = μ₀ 2 I / 4π d
I the present case distance d = r/2
Magnetic field due to one wire at point d = r/2 is
B₁ = μ₀ 2 I / (4π r / 2 )
= 10⁻⁷ x 4I / r
Magnetic field due to the other wire at point d = r/2 is
B₂ = μ₀ 2 I / (4π r / 2 )
= 10⁻⁷ x 4I / r
Direction of magnetic field due to both the wires at the mid point P will be same . It will be in downward direction in the given scenario
So total magnetic field
B = B₁ + B₂
= 2 x 10⁻⁷ x 4I / r
= 8 x 10⁻⁷ x I / r