Exam1 Name: Multiple Choice Questions 5pts each 1. Two thin spherical shells, one with radius 2R and the other with radius R are placed on the table. First sphere has charge IC at the center and second sphere has charge 2C at the center. . The ratio of the number of field lines through the larger sphere to the number of field lines through the smaller is: A) 1 B) 2 C) 4 D) 1/2 E) 1/4 2. A completely ionized beryllium atom (net charge = +4e) is accelerated through a potential difference of 6.0 V. What is the increase in kinetic energy of the atom? A) zero eV B) 0.67 eV C) 4.0 eV D) 6.0 eV E) 24 eV 3. The sketch below shows cross sections of equipotential surfaces between two charged conductors that are shown in solid grey. Various points on the equipotential surfaces near the conductors are labeled A, B, C, ..., I. At which of the labeled points will the electric field have the greatest magnitude? 0.4 m C -70 V G -60 V B -50 V -40 V -30 V -20 V +20 V +40 V 4. The potential difference across the ends of a wire is doubled in magnitude. If Ohm's law is obeyed, which one of the following statements concerning the resistance of the wire is true? A) The resistance is one half of its original value. B) The resistance is twice its original value and current stays the same C) The resistance is not changed and current is doubled. D) The resistance increases by a factor of four. E) The resistance decreases by a factor of four.5. A charge is accelerated in the direction of electric field. What is the nature of the charge. A) positive B) negative C) neutral Problems 6 to10 (15 pts each) 6. An uncharged capacitor and 1MQ resistor are connected in series to a 15-V battery and an open switch to form a simple RC circuit. The switch is closed at t = 0 s. The time constant of the circuit is 5.0 s. a) Determine the value of the Capacitance C. b) What is the charge remaining on either plate after two time constants have elapsed?7. Two charges of opposite sign and equal magnitude Q = 0.82 C are held 2.0 m apart as shown in the figure. Determine the electric potential at the point P. 1.0 m 4.0 m 1.0 m 4.0 m -O 8. Two point particles, Q1 is at origin with charge +8 x 10-9 C and Q2 with charge -2 x 10 9 C, is placed at x=4m. Find the electric field at point 10m.9. Calculate the charge across each capacitor. 20 HF 100 UF 10 V 40 UF10. Calculate the values of I1, I2 and Is for this circuit using Kirchoff's laws. V1=1V, V2= 2 V, V3= 3 V and each resistor is 1 Q resistor. R. 3 R 2 V3 V 2 RA B