MULTIPLE CHOICE 691 A C increases B C decreases C C remains

MULTIPLE CHOICE 691 (A) C increases. (B) C decreases (C) C remains the same (D) There is not enough information to answer the qaestion. a) Which arrangement would have the largest equivalent ca- pacitance? (b) If each arrangement were connected to a 12-V potential difference, in which case would the largest amount of charge be transferred? (c) Each arrangement is connected to a potential difference o that the same amount of charge is transferred. Which requires the largest potential difference? (b) How does the capacitance of this system change if r is de- (C) C remains the same. (D) There is not enough information to answer the question. 4. Which of the following changes to an ideal parallel-plane in an in- 30-3 Calculating the Capacitance 30-5 Energy Storage in an Electric Field capac itor connected to an ideal battery will result in an in1 A parallel-plate capacitior is connected to an ideal battery, crease in the charge on the capacitor? 10A /which provides a fised potential difference. Originally the en- (A) Decreasing the potential difference across the plates (B) Decreasing the area of the plates C) Decreasing the separation of the plates (D) None of the above ergy stored in the capacitor is Uo- If the distance between the plates is doubled, then the new energy stored in the capacitor will be 5. Equation 30-5 neglects fringing effects near the edge of the (D) U2. (E U4 plates. Does this cause Eq. 30-5 to under- or overestimate the 11./A paralle-plate capacitor is charged by connecting it so an capacitance of a real parallel-plate capacitor? ideal battery; the capacitor is then disconnected. Originally the energy stored in the capacitor is Ue. If the distance be- tween the plates is doubled, then the new energy stored in the capacitor will be (C) Neither, the expression is exact 6. What is the capacitance of a single spherical conductor of ra- dius r? (A) 4m (B) 4 (C) 4elr A student originally charges a fixed capacitor to have a poten- tial energy of 1 J. If the student wishes to give the capacitor a (D) Capacitance is undefined for a single object 30-4 Capacitors in Series and Parallel potential energy of 4 J, then the student should (A) quadruple the potential difference across the capacitor (B) double the potential difference across the capacitor but (C) double both the potential difference across the capaci- (D) leave the potential difference across the capacitor un- 7. Two capacitors Ci and C, are connected in series; assume that c, c.. The equivalent capacitance of this arrangement is but leave the charge unchunged. leave the charge unchanged tor and the charge changed while doubling the charge (A) C

Solution

9

Equivalent capacitance for circuit a is 6.

Equivalent capacitance for circuit b is 1.333

Equivalent capacitance for circuit c is 3.

Equivalent capacitance for circuit d is 0.667

Two parallel and two series combination of 4 capacitors equivalent capacitance is 3 so option c is correct