- Watch this video (Links to an external site.). It gives an overview of the lab kit (VERY helpful). Take out the components and play along if you like!
- ⭐️ What is the
**voltage**of your battery? - ⭐️ To make sure you don’t break the multimeter we’re going to calculate the minimum resistance that we can connect to the battery. If you want a maximum possible current of 150 mA, what is the
**smallest resistance**you can attach to your battery? - ⭐️ Create Circuit 1(shown below) using a 20 ohm resistor, your battery, the switch (leave the switch open), and the Ammeter (which is the multimeter set up to measure current).
**Take a picture**of your physical circuit setup and include it here.**NOTE**: Always check the values of resistors before putting them in the circuit using the Multimeter in Ohmmeter mode.

**Circuit 1**

- ⭐️ What is the
**expected current**in this circuit based on Ohm’s Law? - ⭐️ What is the
**actual current**when you close the switch? (don’t forget to open the switch after you measure) - ⭐️ Move the Ammeter in the circuit so that is between the switch and the resistor. What is the
**current**now (when the switch is closed)? - ⭐️ How do the answers of #6 and #7 compare? Are the answers
**consistent with your understanding of current**? - Remove the Ammeter and rebuild the circuit as shown below

**Circuit 1** (without the Ammeter)

- Watch this brief video on measuring voltage in a circuit (Links to an external site.).
- ⭐️ Change the multimeter to Voltmeter mode (using the 2000 mV range). Close the switch. What is the
**voltage**across (i) the battery, (ii) the switch), and (iii) the resistor?**NOTE**: Remember the**battery voltage is positive**and the**other ones are negative**or**zero**. - ⭐️ What does the sum of the voltages add up to? Is it as expected? Explain.
- Open the switch

PART II: 2 Resistor Series Circuit

- Set up Circuit 2 shown below using a
**100 ohm resistor**and a**20 ohm resistor**. This is 2 resistors in series.

**Circuit 2**

- ⭐️ Calculate the expected
**equivalent resistance**of this circuit. - ⭐️ Measure the actual
**equivalent resistance**of this circuit. (make sure the switch is off for this part) - ⭐️ What do you expect the
**current**to be (i) through the battery, (ii) between the resistors? - ⭐️
**Measure the current**at those two points. Is it as expected? - ⭐️ What do you expect the
**voltage drop**across each resistor to be? Explain. - ⭐️
**Measure the voltage**across each resistor. Is it as expected? - Open the switch

PART III: 2 Resistor Parallel Circuit

- Set up Circuit 2 shown below using a
**100 ohm resistor**and a**20 ohm resistor**. This is 2 resistors in parallel.

**Circuit 3**

- ⭐️ Calculate the expected
**equivalent resistance**of this circuit. - ⭐️ Measure the actual
**equivalent resistance**of this circuit. (make sure the switch is off for this part) - ⭐️ What do you expect the
**current**to be through (i) the battery, (ii) the 100 ohm resistor (iii) the 20 ohm resistor? - ⭐️
**Measure the current**at those three points. Is it as expected? - ⭐️ What do you expect the
**voltage drop**across each resistor to be? Explain. - ⭐️
**Measure the voltage**across each resistor. Is it as expected? - Open the switch

PART IV: Equivalent resistance of a 4 Resistor Circuit

- We’re just using resistors and wires for this one: Make up your own circuit using 4 resistors (make sure to choose 4 resistors that aren’t too different from each other and don’t just put them all in series! )
- ⭐️
**Draw a circuit diagram**. Include a picture of your circuit diagram here. - ⭐️ Calculate the expected
**equivalent resistance**of this circuit. (using resistor addition formulas) - ⭐️ Measure the actual
**equivalent resistance**of this circuit.

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