EGR 120 Introduction to Engineering

EGR120: Introduction to Engineering

Homework 1 (25 points)

  1. Watch after 1:50 of&nbspVoltage, Current and Resistance by Bozeman Science. Draw the following circuit using the Circuit Construction Kit (http://tinyurl.com/2u5bnbk).

    1. (5 points) Insert the snapshot of the circuit below this text. You can use the Windows’ snipping tool. A short tutorial can be found here.

Answer:

    1. (2 points) Why is one light bulb brighter than the other one?

Answer: One bulb is brighter because the resistor which is in frontof this bulb has less resistance than the one which is afore thesecond bulb. So, the second resistor has more resistance.

    1. (3 points) If you want to make the dimmer light brighter, what do you need to do?

Answer:You need to reduce the resistance.

  1. Using the lab data of voltage vs current experiment:

    1. (2 points) Plot the data using excel. A short tutorial on excel plots can be found here.

    2. (2 points) Fit a straight (linear) line to the plot. A short tutorial on line fitting using excel can be found here.

    3. (2 points) Insert the snapshot of the plot with the fit curve here:

Answer:

    1. (4 points) Which number on the fit curve represents the value of the resistance? What is the value? Compare it with the experimental data.

The value ofresistance on the first plot is 1.06 Ω and on the second is 0.33 Ω. We can to find the value of resistance by experimental way, actuallyit will be same plus some error of a measurement .

1.063 Ω, 1.077Ω, 1.083 Ω, 1.066 Ω from the first measurement

Current

Voltage

4,8

5,10

3,60

3,88

2,40

2,60

1,20

1,28

0.33 Ω, 0.33 Ω,0.34 Ω, 0.33 Ω from the second measurement

Current

Voltage

4,80

1,59

3,60

1,20

2,40

0,81

1,20

0,40

  1. (5 points) Consider the circuit shown here. Calculate the current when v = 5 volts and the resistance is as specified below. To get full credit, be sure to use the correct prefix (mA, nA, etc.).

1 Ω

50 Ω

1 kΩ

Answer: 5 A

Answer: 100 mA

Answer:5mA