Remember these things: 1. Batteries (or power supplies) are sources of constant potential. For current to flow in a circuit, there must be a closed loop. 3. When the current reaches device, it can either charge that device (like a capacitor), or it must go through the device. No current is ever lost (charge is conserved) 4. Asyou go around a circuit loop with devices there will be drops in electrical potential (voltage) across the two sides of the device if current passes through them. Examine the circuit shown below. A variable DC power supply is like a variable battery. When you turn the dial, you change the voltage (potential difference) between its terminals. owerSupply 106hm - The item labeled \"A\" is a current meter - it measures the current with a very, very small drop in potential (it does not affect the circuit). Current meters are always placed in series. The item labeled \"V\" is a potential meter (volt-meter) - these measure the potential difference across the two sides of the device across which the voltmeter is connected. Volt meters are always placed in parallel and they do not allow current to flow through them (it does not affect the circuit). In the circuit above the current meter measures the current in the circuit (there is only one path and therefore only one current) and the volt meter measures the voltage across the device. Prediction 1: What will happen to the potential difference across the resistor as the dial on the power supply is turned to higher and higher potential? Prediction 2: What will happen to the current through the resistor as you turn the dial on the power supply and increase the applied voltage from zero? Test your prediction. Ask your instructor for a resistor and connect the circuit above. Set the power supply to zero voltage and slowly turn the dial to 0.5V and record the current measured by the ammeter. Continue increasing the voltage slowly to about 3.5 volts in steps of 0.5 V. Record your data in the table below. Make sure to include the uncertainty of the measurements! Resistance of resistor from color code: Potential Difference (volts) Current (Amps)