Download Problem Set - Appoquinimink High School

Problem Set #1 of Marking Period 4
Worth 25 points
Due Monday 4/11/11
Focus: Electricity and Magnetism
1) Using the circuit below, answer the following questions:
a) What is the equivalent resistance of the circuit? (2 points)
b) What is the current measured in ammeter A? (2 points)
c) How does potential difference across the 3 ohm resistor compare to the potential difference
across the 4 ohm resistor? (1 point)
2) An electron is accelerated across a 1200 volt potential difference, as shown in the diagram. Upon
reaching the other side, the electron enters a downward electric field of uniform strength E = 1000 N/C.
The length of the second region, containing the electric field is 1.2 meters.
a) How much work is done to move the electron across the potential difference region? (3 points)
b) What is the velocity of the electron as it enters the electric field region? (3 points)
c) Neglecting the effects of gravity, the electron is deflected away from the straight path.
Calculate the magnitude of the deflected distance, h. (4 points)
3) Two tests are run. In both trials you may ignore the effect of gravity.
Test 1: There are two large parallel plates separated by a distance of d = 0.5m with a potential
difference of 0.12V across them. There is a uniform magnetic field B pointing perpendicularly out of the
paper of strength 0.002T starting to the right of plate 2. An electron is released from rest at plate 1 as
shown below. It passes through a hole in plate 2 and enters the magnetic field and only experiences
forces due to the magnetic field.
Test 2: The same set-up is run with the following two exceptions:
1) The battery is switched so that plate 1 becomes positive and plate 2 becomes negative.
2) A proton is used instead of an electron.
a) Compare the force on each charge. (2 points)
b) Compare the speed of the proton as it emerges from the hole to the speed of the electron as it
emerges from the hole. (3 points)
c) The charges will curve around once they are in the magnetic field. Make a sketch of each path.
(2 points)
d) How far away will the two charges be from each other when the strike the plate? (3 points)