14. Two parallel conducting plates are connected to a constantvoltage source. The magnitude of the elec¬tric field between theplates is 2,000 N/C. If the voltage is doubled and the distancebetween the plates is reduced to 1/5 the original distance, themagnitude of the new electric field is
(A) 800 N/C (B) 1,600 N/C (C) 2,400 N/C (D) 5,000 N/C (E) 20,000N/C
18. What is the potential energy of a particle of charge +q that isheld at point P ?
20. A certain coffeepot draws 4.0 A of current when it is operatedon 120 V household lines. If electrical energy costs 10 cents perkilowatt hour, how much does it cost to operate the coffeepot for 2hours?
(A) 2.4 cents (B) 4.8 cents (C) 8.0 cents (D) 9.6 cents (E) 16cents
21. An electron is in a uniform magnetic field B that is directedout of the plane of the page, as shown above. When the electron ismoving in the plane of the page in the direction indicated by thearrow, the force on the electron is directed
(A) toward the right (B) out of the page (C) into the page (D)toward the top of the page
(E) toward the bottom of the page
14. Two parallel conducting plates are connected to a constantvoltage source. The magnitude of the elec¬tric field between theplates is 2,000 N/C. If the voltage is doubled and the distancebetween the plates is reduced to 1/5 the original distance, themagnitude of the new electric field is
(A) 800 N/C (B) 1,600 N/C (C) 2,400 N/C (D) 5,000 N/C (E) 20,000N/C
18. What is the potential energy of a particle of charge +q that isheld at point P ?
20. A certain coffeepot draws 4.0 A of current when it is operatedon 120 V household lines. If electrical energy costs 10 cents perkilowatt hour, how much does it cost to operate the coffeepot for 2hours?
(A) 2.4 cents (B) 4.8 cents (C) 8.0 cents (D) 9.6 cents (E) 16cents
21. An electron is in a uniform magnetic field B that is directedout of the plane of the page, as shown above. When the electron ismoving in the plane of the page in the direction indicated by thearrow, the force on the electron is directed
(A) toward the right (B) out of the page (C) into the page (D)toward the top of the page
(E) toward the bottom of the page
