B. opposite charge and smaller mass
Answer:
Part a)

Part B)

Part C)

Explanation:
Part a)
Magnetic field due to a long ideal solenoid is given by

n = number of turns per unit length



now we know that magnetic field due to solenoid is


Now magnetic flux due to this magnetic field is given by




Part B)
Now for mutual inductance we know that




now we have


Part C)
As we know that induced EMF is given as



The equation you use is Ke = 1/2mv^2. when you plug in the numbers that are given you get Ke= 1/2(4)(2^2) which gives you a Kinetic Energy of 8
I don't really know what it's about but everything looks okay to me. There might be some mistakes on the last sentence but i'm not completely sure.
Answer:
the answer the correct one is c
Explanation:
Electric charges of different signs attract and those of the same sign repel. In addition, there are two types of insulating bodies, where the loads are fixed (immobile) and metallic (with mobile loads.
Let's analyze the situation presented
* A rod with positive approaches and the sphere is attracted, so the charge on the sphere is negative
* A rod with a negative charge approaches and the sphere is attracted, therefore the charge of the sphere must be positive.
For this to happen, the sphere must be unloaded and the charge that creates the phenomenon are induced charges because the mobile charges of the same sign as the sphere are repelled.
when checking the answer the correct one is c