Q1: If you wish to increase the amount of current in a resistor from 120 mA to 160 mA by changing the 24 V source, what should the new voltage setting be?

ANS:D - 32 V

We'll first find the Resistance.

Let's find it
V=IR,
R=V/I.
R=24/120*10^-3,
R=24*1000/120,
R=24000/120,
R=200 (Ohm).

And now we get the value of resistance that is 200 ( Ohm ).

But we need 160 mA of current that's why now we'll find the value of Voltage and how much voltage is increasing.
Let's find,

V=IR.
V= 160*10^-3 * 200,
V= 160*200/1000,
V= 32000/1000,
V=32v.

THANK YOU.