2. What is the value of a resistor if the current through it is 15.0 mA when a voltage of 45.0 V,is applied?

Ohm's Law states that the voltage (V) across a resistor is equal to the product of the current (I) flowing through it and its resistance (R). Mathematically, this is expressed as V = IR.<br /><br />We are given:<br /><br />* **V (voltage)** = 45.0 V<br />* **I (current)** = 15.0 mA = 0.015 A (Remember to convert milliamps to amps)<br /><br />We need to find R (resistance). Rearranging Ohm's Law formula to solve for R, we get R = V/I.<br /><br />Substituting the given values:<br /><br />R = 45.0 V / 0.015 A = 3000 Ω<br /><br />Therefore, the value of the resistor is $\boxed{3000 \ \Omega}$ (or 3 kΩ).<br />