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
Answer:
Explanation:
The magnitude of the magnetic field on the axis of the ring is given by:
is the permeability of free space, 
is the flowing current through the ring, 
is the ring's radius and 
is the distance to the center of the ring.
The flowing current through the ring is defined as the ring's charge divided into the time taken by the charge to complete one revolution, that is, the period 
. So, we have:
Now, replacing in (1):
If one reverse the orientation of a permanent magnet ITS MAGNETIZATION WILL BE PERMANENTLY REVERSED. This is because, the magnetic domains inside the permanent magnet aligned with the new applied field and increase with it while those domains that are anti aligned with that field will shrink.
<h2>Answer</h2>
option D)
2.4 seconds
<h2>Explanation</h2>
Given in the question,
mass of car = 1200kg
speed of car = 19m/s
Force due to direction of travel
F = ma
= 12000(a)
Force to due frictional force in reverse direction
-F = mg(friction coefficient)
= -12000(9.81)(0.8)
<h2>
-mg(friction coefficient) = ma </h2>
(cancelling mass from both side of equation)
g(0.8) = a
(9.81)(0.8) = a
a = 7.848 m/s²
<h2>Use Newton Law of motion</h2><h3>vf - vo = a • t</h3>
where vf = final velocity
vo = initial velocity
a = acceleration
t = time
0 - 19 = 7.8(t)
t = 19/7.8
= 2.436 s
≈ 2.4s
