In: Physics
1. In the demonstration where a magnet is brought near a loop, what determines the induced current?
the strength of the magnetic field intercepted by the loop |
the rate at which the number of magnetic field lines intercepted by the loop changes |
the spacing of the magnetic field lines intercepted by the loop |
the number of magnetic field lines intercepted by the loop |
2.
Which describes the flux of a magnetic field that is tangent to a section on a closed surface?
The flux is zero. |
The flux is negative. |
The flux is positive. |
3. Which is true about the emf induced in a loop by a magnet?
It is equal to the inverse of the magnetic flux through the loop. |
It is equal to the inverse of the rate at which the magnetic flux through the loop changes. |
It is equal to the rate at which the magnetic flux through the loop changes. |
It is equal to the magnetic flux through the loop. |
4. When the magnetic flux through a loop increases, which is true about the induced current?
It produces a magnetic field in the direction opposite the existing magnetic field. |
It produces a magnetic field but the direction depends on the rate at which the existing field changes. |
It produces a magnetic field in the same direction as the existing magnetic field. |
5. In the demonstration where a loop is pulled out of a magnetic field at constant speed, which is true about the power of your force?
It is less than the power of dissipation by the current. |
It is greater than the power of dissipation by the current. |
It is equal to the power of dissipation by the current. |
1) the rate at which magnetic field lines intercepted by the loopchanges because Current will induced when there is change in magnetic flux.. Other wise current will not induce how much and how many field lines will cross-OPTION(2) is correct
2) the flux is zero because Magnetic field lines are tangent to surface which means they are not perpendicular. Further which means the Magnetic field lines are not passing through the closed surface -OPTION (1) is correct
3) By Faraday law induced end depends upon the rate at the which magnetic flux through the Loop Changes.. OPTION (3) is correct
4) By lenz the direction of induced current will take place in such a way that it will oppose the Reason behind the Change in magnetic Flux.. Therefore It will create a Magnetic field a in opposite direction to Decrease the flux.. OPTION (1) is correct
5) By the law of conservation of energy the power we used to Pull out the loop from Magnetic field is equal to power of dissipation from current.. In order to oppose us.. So we can't take the Loop back from Magnetic Field.. OPTION (3) is correct