<p>Electric Field WS – Physics 2</p><p>1. At a point in space an electron feels an electric force vertically upward. What is the direction of the electric field at that point?</p><p>2. Why can electric field lines never cross?</p><p>3. An isolated electron experiences an electric force of 6.4 x 10-14 N. What is the magnitude of the electric field at -19 that location? (qe = 1.6 x 10 C) </p><p>4. What is the magnitude and direction of an electric field that would just support the weight of an electron? (m = 9.11 x 10-31 kg)</p><p>5. What is the magnitude of the electric field at a point 0.25 cm away from a point charge of +4.0 x 10-6 C?</p><p>6. Two charges, - 4.0 μC and - 5.0 μC, are separated by a distance of 20.0 cm. What is the electric field intensity halfway between the charges? ( 1 μC = 1 x 10-6 C )</p><p>7. Two charges, + 3.0 μC and +4.0 μC, are located at (-0.50m, 0) and (0.75 m, 0), respectively. Where on the x- axis is the electric field zero?</p><p>8. An electron is placed in an electric field of 2.5 x 103 N/C directed along the +y-axis. What is the force on the electron?</p><p>ANSWERS: 3. 4.0 X 105 N/C 4. 5.6 X 10-11 N/C, down 5. 5.8 x 109 N/C 6. 9.0 x 105 N/C toward -5 μC charge 7. (0.080 m , 0) 8. 4.0 x 10-16 N in the –y direction Electric Potential WS (Physics 2)</p><p>1) The electric field intensity between two charged parallel plates is 1.00 x 10-3 N/C. If the plates are 2.55 cm apart, what is the potential difference of the plates?</p><p>2) A rechargeable D-cell has a voltage of 1.25 V. The average distance between the parallel plates which make up this electrochemical cell is 0.850 cm. What is the magnitude of the electric field intensity inside?</p><p>3) During a thunderstorm, then underside of a cloud becomes positively charged, which induces a negative charge on the ground underneath it (just like two parallel plates). If the potential difference between the cloud and the ground is 1.20 gigavolts ( 1 GV = 1 x 109 V) and the electric field intensity between them is 1.92 x 106 N/C, downward, how far above the ground is the bottom of the cloud?</p><p>4) You charge up your pet pit bull by rubbing him on the living room carpet, and you bring him close to the neighbor's cat, to which you have previously given a charge of +3.50 x 10-3 C. (Why, you ask? There's nothing good on TV.) a. If the force acting between them when they are 1.35 m away from each other is an attractive force of 95100 N, what is the charge on the pit bull?</p><p> b. Calculate the electric field intensity at a point midway between the dog and the cat.</p><p> c. Calculate the potential difference between the dog-cat combination.</p><p>ANSWERS: 1. 2.55 x 10-5 V 2. 147 N/C 3. 625 m 4. a. -5.50 x 10-3 C b. 1.78 x 108 N/C, toward pit bull c. 2.40 x 108 V</p>