# Physics

Physics
Homework for CH. 22
Answer all the questions in full details for full credit
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1) Two charges that are separated by one meter exert 1-N forces on each other. If the magnitude of each charge is doubled, the force on each charge is
A) 1 N.
B) 4 N.
C) 2 N.
D) 8 N.
E) none of the above
2) Two charged particles attract each other with a force F. If the charges of both particles are doubled, and the distance between them also doubled, then the force of attraction will be
A) 2 F.
B) F.
C) F/2.
D) F/4.
E) none of the above
3) The electrical force on a 2-C charge is 60 N. The electric field where the charge is located is
A) 60 N/C. B) 20 N/C. C) 240 N/C. D) 30 N/C. E) 120 N/C.

4) The electric field around an isolated electron has a certain strength 1 cm from the electron. The electric field strength 2 cm from the electron is
A) four times as much.
B) twice as much.
C) the same.
D) half as much.
E) none of the above
5) Imagine a single charge q placed at one corner of a square, and that the electric field at the center of the square is F/q. If two other equal charges are placed at the adjacent corners of the square (leaving the opposite corner “blank”), the electric field at the center of the square is
A) F/(2q).
B) F/q.
C) F/(4q).
D) 4F/q.
E) none of the above
6) If 10 J of work is used in pushing 1 C of charge into an electric field, its electric potential relative to its starting position is
A) 10 V. B) less than 10 V.
C) more than 10 V D) none of the above
7) Assume that 10 J of work pushes a charge initially at rest into an electric field. If the charge is then released, it flies back to its starting position with a kinetic energy of
A) more than 10 J.
B) zero.
C) 10 J.
D) 5 J.