Instructor: Branton J. Campbell
Office: N261 ESC, Tel: 422-5758
Office hours: Tuesday 2:00pm to 3:00pm (just before class) or by appointment.
Dec 5, 2006 After announcing last week that there would be no final exam, several students requested that I post a copy of an example exam just for the sake of expanding knowledge. Don't we have great students here at BYU! I post an example here (build and demonstrate 3 of 5 circuits) and invite you to suggest additional problems for me to use in future exams. I'll post the best suggestions here (be sure to tell me if you want your name attached).
1. Use your 10 kW potentiometer to build a non-inverting amplifier with a gain that varies between 1 and 10 (accurate within ±20%) as the pot is turned in the clockwise direction. Demonstrate your circuit by driving your amplifier with a 10 kHz sine wave from your signal generator and simultaneously view the input and output signals on the oscilloscope.
2. Build a circuit involving your 555 timer chip (no signal generator) that brightly turns an incandescent bulb on and off with a 3-second period. Configure the circuit so that light is off for twice as long as it is on during each period, or vice versa. These times must be accurate to within 25%.
3. Build a simple comparator circuit that takes a 5 kHz sine wave (10 V peak to peak) from your signal generator as an input, and outputs 5 V when the input is less than -2.5 V or 0 otherwise. Display the input and output signals together on your oscilloscope
4. Using either flip-flops or your decade counter, build a divide-by-9 counter. Drive the counter with the TTL output of your signal generator at 1 Hz, and use a pair of LEDs (one at the input of the counter and one at the output of the counter) to demonstrate that the period of the output signal is nine seconds, while the period of the input is one second.
5. Build a two-input logic gate with an output that goes high (5V, logical 1) when the inputs are different and low (0V, logical 0) otherwise. Operate the inputs with push-button switches so that a pressed button yields a logical 1, while an unpressed button yields a logical 0. Demonstrate the circuit by driving an LED output.
Nov 28, 2006
Because of the unusually large number of students enrolled in Physics 140 this
semester (more than double the average due to the course# change), I have
decided not to administer a final exam. While a final exam does reinforce
learning, even for a 1-credit lab course, it just isn't practical to give the
usual 3-hour hands-on exam to each of eight sections separately. As a
result, your 14 lab scores will now determine 100% of your final grade. I
know that you are dissappointed ... Perhaps you can cheer yourself up by
designing an amazing new Christmas-tree light controller for your apartment that
blinks on and off to the beat of a good tune.
Sep 1, 2006 The required Physics 140 course packet is now available in the bookstore. The last-minute increase in course enrollment may cause the bookstore to run short -- so don't be the last one in line.
Sep 1, 2006 Each student will purchase a lab kit at a cost of $26.00 (cash or check only) which contains the electronic components required to complete the 14 labs described in the course packet. The kits will be available for purchase just outside the lecture hall during the 15 minutes immediately before and after class on Sept 12th. We hope that all students will come prepared to purchase their kits at that time. Alternatively, you can purchase your kit in N231 ESC during regular business hours.