So we need to find the formula for magnetic field B using the current (I) and the distance from the probe (d). So, We know that the stronger the current I, the stronger the magnetic field B. That tells us that the I and B are proportional. Also we know that the strength of the magnetic field B is weaker as the distance d of the probe increases. That tells us that B and d are inversely proportional. So our formula should have B=(I/d)*c where c is a constant of proportionality. c=μ₀/2π where μ₀ is the permeability of free space. So finally our formula is B=(μ₀I)/(2πd).
Answer:
Please find the answer in the explanation
Explanation:
Friction is a force that opposes motion. One or two of the advantages of friction are break and ability of an object to walk.
Writing yes it is useful because when your writing because friction helps you see what your writing
ii. Rubbing. Yes, it is useful.
friction make it possible for two object to rub each other
iii. Skiing. No. It is not useful because With presence of friction, skiing will not be possible.
iv. Rotating a wheel No. It is not useful because Friction will oppose the rotation of the wheel.
Answer:
108.7 V
Explanation:
Two forces are acting on the particle:
- The external force, whose work is 
- The force of the electric field, whose work is equal to the change in electric potential energy of the charge: 
where
q is the charge
is the potential difference
The variation of kinetic energy of the charge is equal to the sum of the work done by the two forces:
and since the charge starts from rest, 
, so the formula becomes
In this problem, we have
is the work done by the external force
is the charge
is the final kinetic energy
Solving the formula for , we find
