An airplane black box contains a bunch of unknown resistances and batteries con- nected in unknown way such that (1) a 9 Ohm resistor across the terminals of the circuit box draws 0.80 A, and (2) an 17 Ohm resistor draws 0.50 A. What resistance will draw 0.12 A

The unknown resistance which will draw a current of 0.12 A is 84.5 ohm

Explanation:

Let say the emf of the cell is E and internal resistance of the system is "r"

now we will have

here we have 9 ohm resistance draw current of 0.80 A

also we know that 17 ohm resistance will draw current of 0.50 A

so we will have

also we have

now when 0.12 A current is drawn across unknown resistance then we have

so we have

a charge 3q is at the origin, and a charge −2q is on the positive x axis at x=a. part a where on the x-axis would you place a third charge so it would experience no net electric force? enter an expression for the exact answer, which will involve a square-root sign. (do not enter an approximate decimal answer.)

explanation:

could i give you a exaplo that could you?