mizel
Newbie level 4
interview question for cdma
I actually considered using the areas, I'm just not sure how to calculate the area of a triangle without using angles.
The only equations I remember are A = 1/2(b*h) or A = a*b*sin(C) where C is the angle of intersection of a and b.
It has been a while since I took geometry so maybe I have forgotten.
I feel bad detracting from the topic so here are some questions I have seen:
Suppose you had a sensor with an analog output, how would you read the output onto a computer? From a high level perspective what would you need?
Amplifier, ADC, signal level converter.
Where should the amp be placed, closer to the sensor or the computer?
Closer to sensor to avoid amplifying noise.
What is the resolution of the ADC? How can it be adjusted if you have information about the noise levels in the systems?
Resolution: size of the window the ADC is accurate within. The number of bits used to represent the analog value dictates resolution. 4 bits --> 2^4 = 16 values. resolution is range of values divided by 16. Ex. -5 to 5V signal resolution = 10/16V resolution.
If the noise is +-.05V, the window size (step size) should be double that ~.1V.
This was for a general engineering job. The questions are usually more difficult if the interview is for something specialized. For example EDA, VLSI, RF Electronics, Power, Comp. Architecture, Communications, etc.
I actually considered using the areas, I'm just not sure how to calculate the area of a triangle without using angles.
The only equations I remember are A = 1/2(b*h) or A = a*b*sin(C) where C is the angle of intersection of a and b.
It has been a while since I took geometry so maybe I have forgotten.
I feel bad detracting from the topic so here are some questions I have seen:
Suppose you had a sensor with an analog output, how would you read the output onto a computer? From a high level perspective what would you need?
Amplifier, ADC, signal level converter.
Where should the amp be placed, closer to the sensor or the computer?
Closer to sensor to avoid amplifying noise.
What is the resolution of the ADC? How can it be adjusted if you have information about the noise levels in the systems?
Resolution: size of the window the ADC is accurate within. The number of bits used to represent the analog value dictates resolution. 4 bits --> 2^4 = 16 values. resolution is range of values divided by 16. Ex. -5 to 5V signal resolution = 10/16V resolution.
If the noise is +-.05V, the window size (step size) should be double that ~.1V.
This was for a general engineering job. The questions are usually more difficult if the interview is for something specialized. For example EDA, VLSI, RF Electronics, Power, Comp. Architecture, Communications, etc.