2049_ch25B

# 2049_ch25B - ConcepTest Two identical parallel plate...

This preview shows pages 1–6. Sign up to view the full content.

20 PHY2049: Chapter 25 ConcepTest Two identical parallel plate capacitors are shown in an end-view in Figure A. Each has a capacitance of C. If the two are joined together at the edges as in Figure B, forming a single capacitor, what is the final capacitance? (a) C/2 (b) C (c) 2C (d) 0 (e) Need more information A B Area is doubled

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

View Full Document
21 PHY2049: Chapter 25 ConcepTest Each capacitor is the same in the three configurations. Which configuration has the lowest equivalent capacitance? (1) A (2) B (3) C (4) They all have identical capacitance C C C C C A B C C/2 (series)
22 PHY2054: Chapter 16 Capacitance Example: Find Charges on Series Capacitors Let V = 10, C 1 = 6 Ж F, C 2 = 12 Ж F Find charges, voltages on C 1 , C 2 Combine series capacitances This is what battery “sees”! Find q eq , then use q eq = q 1 = q 2 q eq = C eq V = 4 x 10 = 40 Ж C Find V 1 , V 2 V 1 = q 1 / C 1 = 40 / 6 = 6.67 V V 2 = q 2 / C 2 = 40 / 12 = 3.33 V V 1 + V 2 = 10, as expected

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

View Full Document
23 PHY2049: Chapter 25 Energy in a Capacitor Capacitors have energy associated with them Grab a charged capacitor with two hands and find out! Calculate energy Continually move charge from – to + surface dU = V dq V = q / C So capacitors store and release energy as they acquire and release charge This energy is available to drive circuits U = V dq 0 Q = q C dq 0 Q = Q 2 2 C = 1 2 CV 2
24 PHY2049: Chapter 25 Where is the Energy Stored? Answer: Energy is stored in the electric field itself!!

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 02/28/2012 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.

### Page1 / 20

2049_ch25B - ConcepTest Two identical parallel plate...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online