5 Assessment
Friday, 20 July 2018
3:35 PM
When all lab work is completed, you will be asked by a lab tutor to:
Carefully measure eight 1.0 kΩ resistors. Determine the average value of resistance. Then find the deviation, in ohms, of each resistor from the average by computing the amount each value differs from the average. The average deviation can then be found by computing the average of the deviations. Summarize your findings. Are any resistors outside the marked tolerance? Is there any evidence that all resistors are either higher or lower than their marked values?

Construct a circuit which dims an LED using a fixed 5 V DC power supply. An LED uses a small current to emit light. LEDs emit light only when there is current in one direction. To limit the current to a level that is safe for the LEDs, a 390 Ω resistor is placed in series with the LED, as shown in the figure below:

The dimmer will consist of a 10 kΩ potentiometer. Be sure to check the polarity of the LED - if it is installed backwards, it will not light. 

Show and explain Plot 2-1.

Show and explain Plot 2-2. 
Each assessment question is worth a mark of 0.5.

The total mark for this lab activity is 2.