The freezing point of the water is 0 C , and it equals to 273 K
Then, To convert from Kelvins degrees to Celsius degrees we use the relation
Also,
A series circuit has only one path for current,
while a parallel circuit has more than one.
Answer:
position 1 and 4................
R 3/4 = (R3 * R4) / (R3 + R 4) = ( 9 * 18 ) /(9 + 18 ) = 162 / 27 = 6 Ohms
R e = R 1 + R 2 + R 3/4 + R 5 = 3 + 6 + 6 + 15 = 30 Ohms
I = U / Re = 90 V / 30 Ohms = 3 A
Finally for the voltage U 3/4 ( the parallel portion of the circuit ):
U 3/4 = 6 Ohms * 3 A = 18 V
Answer: 18 V