(c) If r is doubled, A increases by a factor of 4. C increases by a factor of 4 and Q increases by a factor of 4. Reflect: When the plates are moved apart, less charge on the plates is required to produce the same potential differ-ence. With the separation of the plates constant, the electric field must remain constant to produce the same potential difference. The electric field depends on the surface charge density, To produce the same more charge is required when the area increases. 18.42. Set Up: Solve: (a) 12.0 V (b) (i) When d is doubled, C is halved. and Q is constant, so V doubles. (ii) When r is doubled, A increases by a factor of 4. V decreases by a factor of 4 and 18.43. Set Up: We measure that the diameter of a quarter is 24.5 mm, so Solve: (a) (b) 18.44. Set Up: Solve: (a) so (b) 18.45. Set Up: Solve: Reflect: C for a capacitor depends only on the dimensions of the capacitor. 18.46. Set Up:
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This note was uploaded on 03/06/2009 for the course PHYS 114 taught by Professor Shoberg during the Spring '07 term at Pittsburg State Uiversity.