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Question

1) A 24 V battery is connected across two metal plates separated by 0.37 cm. Find the magnitude of the electric field.
2) An ion is displaced through a potential difference of 56.0 V and has an increase of electrical potential energy of 2.00x10^-17 J. Calculate the charge on the ion.
3) The magnitude of a uniform electric field between the two plates is about 1.0x10^6 N/C. If the distance between these plates is 2.0 cm, find the potential difference between the plates.
4) An electron is displaced from a point 46 cm away from a proton to a point 121 cm away from the proton. What is the change in the electrical potential energy as a result of this movement?
5) A point charge of 9.00x10^-9 C is located at the origin. A positive charge of 2.80x10^-9 C is brought in from infinity to a point that is exactly 2.40 cm away from the 9.00x10^-9 C charge. What's the change in electrical potential energy?
6) How can electric potential be high when electrical potential energy is relatively low?

7) The potential difference between a pair of oppositely charged plates is 480 V. (a) If the spacing between the plates is doubled without altering the charge on the plates, what is the new potential difference between the plates? (b) If the plate spacing is doubled while the potential difference between the plates is kept constant, what is the ratio of the final charge on one of the plates to the original charge?
8) Clearly distinguish between "electrical potential energy" and "electric potential".
9) Charge must be present at a location in order for there to be electrical potential energy. Must charge also be present at a location for there to be electric potential? Explain.
10) Is it correct to say that an object with twice the electric potential of another has twice the electrical potential energy? Explain.
11) If the potential difference across a capacitor is tripled, by what factor is the electrical potential energy stored in the capacitor multiplied?

12) (a) If you do 11 J of work to push 0.004 C of charge from point A to point B in an electric field, what is the voltage difference between points A and B?
(b) When the charge is released, what will be its kinetic energy as it flies back past its starting point A?
(c) What principle guides your answer?Conservation of mass, conservation of momentum, conservation of energy,conservation of charge, or none of these.
13) (a) Suppose that you start with a charge of 0.006 C and find that it takes 26 J of work to move it from point A to point B. What is the voltage difference between points A and B?(b) If this charge is released, what will be its kinetic energy as it flies back past point A?
14) (a) If a proton is released from rest in a uniform electric field, does the corresponding electric potential at the proton's changing locations increase, decrease, or remain the same?
(b) Does the electrical potential energy increase, decrease, or remain the same?

Answer 1

1. A 24 V battery is connected across two metal plates separated by 0.37 cm. Find the magnitude of the electric field.

E=V/d= 24V / 0.0037m=6487 N/C

2. ) An ion is displaced through a potential difference of 56.0 V and has an increase of electrical potential energy of 2.00x10^-17 J. Calculate the charge on the ion.

Pe=Vq
q=pE/v=
q=2.00E-17Joules/56.0 Volts =3.57 E-19 C

3) The magnitude of a uniform electric field between the two plates is about 1.0x10^6 N/C. If the distance between these plates is 2.0 cm, find the potential difference between the plates.

V=E d
V=1E+6 N/C x .02m=2E+4 Volts


4) An electron is displaced from a point 46 cm away from a proton to a point 121 cm away from the proton. What is the change in the electrical potential energy as a result of this movement?

F=k q1 q2/R^2

dPe=(k q1 q2/R^2) dR
Pe= -(k q1 q2)(1/R2-1/R1) R1=0.46m; R2=1.21m
also q1=q2
and so on...

Post each as an individual question.