phy114 lab4

# phy114 lab4 - Capacitors Objective The objective of the lab...

This preview shows pages 1–3. Sign up to view the full content.

Capacitors Objective: The objective of the lab was to investigate the nature of capacitors and electrostatics. Capacitors are capable of storing electric charges, and can be made with two parallel conducting plates separated by a layer of insulating material such as plastic film. The charge stored by the capacitor is related to the capacitance of the capacitor C and the voltage difference between the two conducting plates across the capacitor, V. This relationship is governed by the equation Q=C V, where Q stands for charge. Therefore, Q, can be calculated if C, a constant, and V, measurable using a Digital Voltmeter, are known. Electric charges are transferable between capacitors, so that charges will be distributed from a charged capacitor to a discharged capacitor. However charges cannot be destroyed nor created so that the total charge on one capacitor must be equal to the final charge on both capacitors after contact. In this case what changes is the voltage, which can be measured using a DVM. The measured or observed final voltage should be close to the theoretical value C1V/(C1+C2). Similarly, when a charged capacitor is connected to a resistor, the charges will transfer to the resistor where it is turned into heat. This process follows an exponential decay model and is governed by the equation Q(t)=Q0e^(-t/RC), where RC is a constant. Procedure: First, voltage follower unit was setup and properly connected to the DVM. Next, a glass rod was rubbed against a cloth, and the glass rod was placed to touch the input of the voltage follower, the reading on the DVM was recorded. Next, a rubber rod was rubbed with the same cloth and placed against the input once again, the reading was again recorded. Then, the voltage follower, with its inherit .1uF capacitor, was connected to a

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
breadboard unit with 5V supply using special leads with minigrabbers ends. The charge stored on the capacitor was calculated. Afterwards, a 1uF capacitor was placed into the
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/29/2008 for the course PHY 114 taught by Professor Tsen during the Fall '08 term at ASU.

### Page1 / 5

phy114 lab4 - Capacitors Objective The objective of the lab...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online