No ice is either 32 degrees Fahrenheit or 0 degrees Celsius but that's only normal ice, dry ice is a different story but I'm assuming you're talking about normal ice
Answer: option c.
Explanation: 3 identical resistors can only have 3 configurations
1) all 3 resistors in series
2) all 3 resistors in parallel
3) 2 parallel resistors in series with 1 resistor.
Case 1 : all 3 resistors in series
Let us assume each of the resistor has resistance value R.
The total resistor (Rt) of 3 resistors in series is given as
Rt = R1 + R2 + R3
Since R1=R2=R3=R
Rt = R+R+R = 3R.
Case 2: all 3 resistors in parallel.
The equivalent resistance of resistors in parallel is given by the formulae below.
1/Rt = 1/R1 + 1/R2 + 1/R3
Since R1=R2=R3=R
1/Rt = 1/R + 1/R + 1/R
1/Rt = 1 +1 +1/ R
1/Rt = 3/R
3 * Rt = R
Rt = R/3
Case 3: 2 parallel resistor in series with one
First is to get the equivalent resistance of the 2 parallel resistor.
1/Rt = 1/R1 + 1/R2
But R1=R2=R
1/Rt = 1/R + 1/R
1/Rt = 1 + 1/R
1/Rt = 2/R
2 *Rt = R
Rt =R/2.
R/2 in series with R has an equivalent resistance as shown below
Rt = R/2 + R
Rt = R + 2R/2
Rt = 3R/2
Since all the possible 3 configuration are listed above and there is no other then option c ( 2R/3) is not possible to achieve
Answer
D. move a small magnet back and forth within a section of the coiled wire.
Explanation:
i put that for the test and i got it right
