Question

A 100 V battery is connected across a
resistor and causes 5 mA current to flow.
Determine the resistance of the resistor.
If the voltage is now reduced to 25 V,
what will be the new value of the current
flowing?

Answer 1

1 mA = 0.001 A

Therefore, 5 mA = 0.001 * 5

=0.005 A

Resistance = voltage / current

= 100 / 0.005

= 20000 ohms

Current = voltage / resistance

= 25 / 20000

= 0.00125 A (or) 1.25 mA