A20.0 ω, 15.0 ω, and 7.00 ω resistor are connected in parallel to an emf source. a current of 7.00 a is in the 15.0 ω resistor. calculate the equivalent resistance of the circuit. answer in units of ω.
what is the potential difference across the source?
answer in units of v.
calculate the current in the 20.0 ω resistor. answer in units of a.

PART A)

Equivalent resistance in parallel is given as

now we have

PART B)

since potential difference across all resistance will remain same as all are in parallel

so here we can use ohm's law

As we know i = 7 A current flows through 15 ohm resistance

PART C)

Similarly ohm's law for 20 ohm resistance we can say

nah.   i'm just sleepy.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it