Question

21. A resistor has a resistance of 176 ohms. How many of these resistors should be connected in parallel so tha'
their combination draws a current of 5 amperes from a 220' volt supply line?
220 volt supply line?​

Answer 1

according to OHM's Law, we have

                                                V=IR

                                      where V=Voltage

                                                   I=Current

                                                   R=resistance

                                      so we have, 220=R*5

                                                           R=44 ohms

as we know that for calculating parallel resistance = 1/R=1/R1+1/R2+....+1/Rn

let the total number of 176ohm resistors be n

1/44=total number of 176ohms resistors*1/176

1/44=n*1/176

n=176/44

n=4

So we need 4 resistors to draw current of 5A from 220 V line.