12 V is the f.e.m.
of the battery. The potential difference that is applied to the motor is actually the fem minus the voltage drop on the internal resistance r:
this is equal to the voltage drop on the resistance of the motor R:
so we can write:
and using
and
we can find the current I:
Answer:
Germanium
Explanation:
Germanium is a chemical element that is grayish white metalliod
Answer:
Correct answer is option D
- Wire is on the cylinder axis and carries current i in the direction opposite to that of the current in the shell
Explanation:
- It cannot be Option E, because the magnetic field outside the wire would not be 0 due to the current carried by the conductor
-Also, the parallel wire cannot carry current in the same direction because, that would amplify the magnetic field created by the outer cylinder (since B is dir. proportional to the current) -and now, that leaves only option C and D. If, it is Option C, then that means one side of the cylinder would be more closer to the parallel wire than the other, so there would be different B fields on the two opposite sides of the cylinder. So, that means the answer is option D.