It is c that’s what it is that’s the answer
Answer:
The magnetic field at the center of a circular loop is
.
Explanation:
Given that,
Radius = 4.0 cm
Current = 2.0 A
We need to calculate the magnetic field at the center of a circular loop
Using formula of magnetic field

Where, I = current
r = radius
Put the value into the formula



Hence, The magnetic field at the center of a circular loop is
.
Answer:
a) v=2.743m/s
b) 
c) T=2.543N
Explanation:
First, calculate the height of the ball at the starting point:


At this point, just in the moment the ball is released, all the energy of the system is potencial gravitational energy. When it is at the bottom all the potencial energy is transformed into kinetic energy:

Solving for v:

if h is the height loss: (l-y')
v=2.743m/s
The centripetal acceleration is the acceleration caused by the tension force exercised by the string, and is pointing outside of the trayectory path (at the lowest point, directly dawn):


To calculate tension, just make the free body diagram of forces in the ball, noticing the existence of the centripetal acceleration:

Answer:
b) field is zero, c) the magnetic field does not change in intensity or direction
e) M = -H = Bo /μ₀
, g) M = 0
Explanation:
Part b
superconductors are formed by so-called Coper pairs that are electrons linked through a distortion in the network, this creates that they must be treated as an entity so we have an even number of charge carriers and the material must behave with diamagnetic , Meissner effect, consequently the magnetic field inside its superconductor is zero
the correct answer is Zero
Part c
outside the superconducting cylinder the magnetic field does not change in intensity or direction
Part E
Magnetization is defined by the equation
B = μ₀ (H + M)
with field B it is zero inside the superconductors
M = -H = Bo /μ₀
where Bo is the magnetic induction in the normal state
Part g
As outside the cylinder there is no material zero magnetization
M = 0