<h3><u>Answer;</u></h3>
C. 12 units
<h3><u>Explanation;</u></h3>
- If the strength of the magnetic field at B is 3 units, the strength of the magnetic field at A is 12 units
- Magnetic field strength is one of two ways that the intensity of a magnetic field can be expressed.
- <em><u>The strength of the field is inversely proportional to the square of the distance from the source. This means that If the distance between two points in magnetic filed is doubled the magnetic force between them will fall to a quarter of the initial value. </u></em>
- <em><u>On the other hand, if the distance between two magnets is halved the magnetic force between them will increase to four times the initial value.</u></em>
I think the correct answers from the choices listed above are options 1, 5 and 7. Angular momentum quantum number determine the energy of an orbital, the shape of the orbital and <span>the overall size of an orbital. Hope this answers the question.</span>
C. when the circuit is closed
Answer:
B) Friction
Explanation:
Friction is a force that acts when an object is sliding along a surface. Microscopically, this force is due to the fact that the two surfaces are not perfectly smooth, but they have "imperfections" that cause a force that opposes the motion of the object.
For an object sliding on a flat surface, the force of friction has magnitude:
where
is the coefficient of kinetic friction
m is the mass of the object
g is the acceleration of gravity
The direction of the force of friction is always opposite to the direction of motion of the object.
In reality, friction also acts if the object is at rest and it is pushed by a force; in this case, we talk about static friction, and its magnitude is
where 
is called coefficient of static friction, and it is generally larger than the coefficient of kinetic friction.
