ME 360 – Spring 2007 Semester
Test #1
2/14/07
Closed book, closed notes portion of test. When you turn in this part of the test you will get the second part
which allows a page of handwritten formulas. There are 25 points on the 1st part and 75 on the 2nd part.
True/False Questions (1 point each)
____1. The minimum gain for an inverting op-amp circuit is -1.
____2. With normally distributed data, about 95% of the data will fall between the mean value and
the mean value ± 2σ.
____3. Bias errors can be detected and removed by statistical methods.
____4. High input impedance is desirable in measuring devices, since they will draw very little current from
the measured system.
____5. Uncertainty is an estimate of the limits of error in a measurement.
____6. Resolution is the difference among repeated measurements of the same quantity.
____7. Range is the difference between the minimum and maximum inputs that produces a valid output.
____8. Precision is the change in output per change in input (slope of output vs. input line).
9.[5] A 314 rad/sec, 4 volt (peak-to-peak) triangle wave is applied to a single input, inverting amplifier with
a gain of -0.5. Sketch the input and output waveforms on the “scope” screen below.
Vertical
Sensitivity
500 mV/div
Horizontal Sensitivity: 2 msec/div
Over
10.[4] A Brazilian-made electric winch for my Ford Ranger pickup is rated at 9.0 kN. What is this load
rating in pounds?
11.[4] Determine the equivalent capacitance of a 0.0047 μF and 2200 pF capacitor placed in parallel.
12.[4] Determine the equivalent resistance of a 470kΩ and 1.0 MΩ resistor placed in parallel.
13.[4] Write the computed uncertainty formula for the following equation using the simplified method.
Assume that every parameter in the equation has uncertainty.
ω=
d 4G
8D 3 N m
Over
ME 360 – Spring 2007 Semester
Test #1
2/14/07
Closed book, closed notes, one 8.5x11 inch hand-written formula sheet allowed. Work the problem in the
space provided below each problem.
14.[25] Determine the nominal deflection, y, and the uncertainty in the deflection, Uy, of a
steel cantilever beam with a rectangular cross-section if the following nominal values
and uncertainties are given for the measured parameters:
I = 0.020 in4 (assume exact)
L = 1.73 ± 0.02 feet
P = 50 lbf ± 1 lb
PL3
y=
3EI
Esteel ~ 29.6 x 106 psi ± 2%
15.[10] Using a 10 bit, bipolar, ±5 volt A/D converter, what range of input voltages corresponds to the
digital value 965?
16.[10] A set of 60 resistors are measured with a DMM to have a mean value of 46.73 kΩ and a standard
deviation of S=0.65 kΩ. The DMM’s manufacturer’s spec sheet indicates that the resistance
measurements are ±0.2% + 3 digits. What is your estimate of the combined uncertainty for the mean
value of the resistors?
17.[30] Design a circuit that will convert the input values to the output values in
the table on the right. You have available several resistors with these values :
1kΩ, 2.2kΩ, 4.7kΩ, 10kΩ, 22kΩ, 47kΩ and 100kΩ.
a) Draw a schematic diagram of your circuit, showing all resistors, power, and
input/output connections.
Input, Ein Output, Eout
volts
volts
-1.65
-6.93
-0.32
-1.34
0.57
2.39
1.73
7.27
+
b) Draw all power connections from the four terminal posts to the solderless breadboard below. Follow
the ME 360 color/row code while making these connections.
c) Draw your circuit on the breadboard below. Show all input/output connections to the circuit. Draw
resistors like this
47 k
+12V +5V Com -12V
Ein
+
-
+
741
-
Eout