Question

1.) A set of 525 ohm resistors are connected to a 12.5 V battery. How would you connect the resistors to achieve the minimum resistance and maximum resistance? what are the minimum and maximum resistance possible with five resistors? What are the minimum and maximum currents when connected to the battery?

2.) A small circle loop is inside a square loop. the large square loop of wire is connected to a battery and experiences a rapidly increasing current in a clockwise direction. What is the direction of the induced current in the smaller circle loop. Explain your answer thoroughly

Answer 1

1. To achieve maximum resistance the resistors should be connected in series and for minimum resistance it should be connected in parallel.

For 5 resistors

Maximum resistance = 525 +525+525+525+525 = 5*525 ohm = 2625 ohm

Minimum resistance =

Maximum current =

Minimum current =

2. By the right hand curl rule, according to which if the thumb of the right hand gives the direction of current the curl of the fingers give the magnetic field direction. As current is clockwise the magnetic field is perpendicular into the paper. The direction of current induced will be given by Lenz law, according to which the direction is such that it opposes the magnetic field that produces it. Therefore as the magnetic field is increasing in perpendicular inside the paper direction the magnetic field due to the current needs to be perpendicular outside the paper direction.

Hence the direction of current will be anti-clockwise.