Question

P3. A long conducting rod of radius a 3.2 mm is surrounded by an equally long.conxial conduct cylindrical shell of radius b-32 mm. The electric charge on a 5.0 m section of the rod is 4.5 x 10°C and the same length section of the shell carries a charge of 2.0 x 10°C. Fig b-crossectional view Figa - side view a. (2) Calculate the electrie charge on the interior and (ii) exterior surface of the 5.0 m long section of the shell b. (7) On Fig. b, sketch the electric field lines inside the rod between the red and the shell, and outside the shell. c. (5) Using Gauss' law, calculate the magnitude of the electric field at a point, 1.8 mm from center of the conducting rod. d. (5) Using Gauss' law, calculate the magnitude of the electric field at a point, 16 mm from the center of the conducting rod. (6) Using Gauss' law, calculate the magnitude of the clectric field at a point, 64 mm from the center of the conducting rod. 2 Place your answers here a. (1). Qinterior (11). Qexterior b. Sketch fields lines on Fig.b, above. (7) c. Ei d. Ez = 4. Es

Answer 1

b+ bl2 c a = 3.2 mm b= 32 mm x = 4.5x10-6 0.9x10 9,= 4.5x106c = 4 - 9.0x166 22 = – 9.0x10c - =-1.881 ar is – a = – 4.5x10oC. (11) - ² – get q = -9.0x108 +4.5x100 = -4.5x10-G interior = -4.5x100 c exterig = – 4.5 x105 c 1

c. d. E, = 0 Ez = (ainside =o). 2K), = 2x9x 10 x 0.9x10 16x10-3 = 1x100 NIC e. Ez = 2x(21+x2) r - 2xgx10 s (-0.9x10) No 64610-3 = 2.5 10 Nic