Charles law Essay

Aim To investigate how the charge on a optical condenser is related to the p. d. applied across it by charging the optical condenser at a constant rate. Apparatus o Capacitor (electrolytic type) 500 ? F o Microammeter 100 ? A o Clip comp cardinalnt holder o Stop-watch o scope o Connecting leads Theory From definition, the condenser C of a optical condenser is found from C = Q/V Where Q is the charge stored on the optical condenser and V is the potential difference across it. == Q = CV ==.If a capacity is charged up at a constant rate, i. e., where I is a constant. Then is also constant. Hence the potential difference across the capacitor increases linearly with time. Procedure 1. The circuit was connected as shown in the elaborate below. The range was set to d. c. and the sensitivity to 1 V/cm. 2. The time plate was set to any high look upon so that a unshakable horizontal trace is displayed. The trace was shifted to the bottom of the screen. 3. The capacitor was shorted bulge by connecting a lead across it and adjust the 100 k ? mickle for a suitable current, say 80 ?A. 4. Shorting lead was removed and the capacitor will charge up. Note what happens to the microammeter reading and the CRO trace. 5. The procedure was iterate but this time start the stop-watch and continuously adjust the potentiometer to come up the current constant as the capacitor charges up. 6. The times was measured for the CRO trace to move up by 1 cm, 2 cm, 3 cm, and so on These are the times for the p. d. across the capacitor to reach 1V, 2V, 3V, etc. 7. The results was tabulated. Results and discussion.8 Describe what happens to the microammeter reading and the CRO trace as the capacitor is being charged up. The microammeter reading increase momentarily, then it decrease to zero point in a few second. After the capacitor had been completely charged,the CRO trace is a horizontal line, which continuously move up. 9 shelve the times for the p. d. across the capacitor to re ach 1 V, 2 V, 3 V, etc. as below P. d. across capacitor Plot a graph of p. d. across the capacitor against time.How is the p. d. related to the time? p. d. is promptly comparative to time. 11 Deduce a relationship between the charge on the capacitor and the p. d. across it. From the graph it is found that p. d. is directly proportional to time. Since Q=CV = V=Q/C Therefore if V across the capacitor is directly proportional to t, Q is directly proportional to time as current was constant. terminus We can find out that the p. d. across the capacitor is directly proportional to the time needed. Given that the charging current is constant. Sharing.The experiment is much easier than the last one , but we encountered some obstacles in connecting wires , as usual , we messed up despotic and negative terminals and couldnt conduct it smoothly. At last, we had to call for help. Suggestion and at that place may be some personal error , for example enumeration the time taken for the capac itor be charged to extent value was rather inaccurate. Perhaps, we could conduct the experiment several times and compute out the average value.Reference list http//en. wikipedia. org/wiki/Capacitor http//www. elecsound. cn/Ceramic-Capacitor. htm.