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1. A proton is accelerated by a constant electric field of magnitude 100 N/C. Using ,the equations of motion with constant acceleration find the proton's speed after 1.OO x 10" s, assuming it starts from rest. I Comment [ASl]: Correct answer ] 2. An electron is sent at high speed toward a gold nucleus (charge +79e). What is the electrical force acting on the electron when it is 3.0 x 10-l4 m away from the gold nucleus? (e = 1.6 x 10-l9 C, k, = 8.99 x 1o9 N.rn2/c2) F = k pg/ rL - (comment [AS2]: Correct answer = 7 kdep~c) r2 3. A square loop with sides of length 50 cm is placed in a uniform electric field such that the electric field makes an angle of 45" to the perpendicular direction of the loop. If the electric field strength is 500 N/C what is the electric flux through the loop? I Comment [AS3]: Correct answer I 4. A charge of +2 C is at the origin. When charge Q is placed at 2 m along the positive x axis, theb-dat 2 m along the negative x axis becomes zero. What is the value of Q? 2m I - -2m I +2c Q Comment [AS4]: Correct answer 5. What is the equivalent capacitance between points and b? All capacitors are 1.0 PF- h m m e n t [ASS]: Correct answer ] Comment [AS6]: Correct answer 1 6. A "sandwich" is constructed of two flat pieces of metal (2.00 cm on a side) with a 2.00-mm-thick piece of a dielectric called Rutile ( K = 100) in between them. What is the capacitance? (a = 8.85 x 10-l2 ~ ~ h l - r n ~ ) . 7. A 0.25-pF capacitor is connected to a 400-V battery. Find the charge on the capacitor. Comment CAS7I: Correct answer Two capacitors Cl = 20-pF and C2= 5-pF are connected in series and charged with a 100-V power supply. What is the total energy stored in the two capacitors? 9. A flashlight bulb operating at a voltage of 4.5 V has a resistance of 8.0 a. How many electrons pass through the bulb filament per second (e = 1.6 x 10-lgC)? 1 10. A metallic conductor has a resistivity of 19 x R-m. What is the resistance of a piece of this conductor that is 30 m long and has a diameter of 2 mm? dj ~ * * c c = Q * O O 2 r c \ Comment [ASlO]: Correct answer ---- -- -- 1 11. 150, 0.5-W decorative lightbulbs are connected in parallel on a string of lights which is connected to a 120-V source. What current is delivered to the lights by the source? 12. A 20-0 platinum wire at 20°C with a temperature coefficient of resistivity of 3.9 x 10" ("c)-' will have what resistance at 100°C? 26R d. 28 R e. 32 R = Odds4 Comment [AS12]: Correct answer C. R,z aoa , K = 20°c , T= lodoc ]