May
2004, Issue 166
Test Your EQ
Each
month, Test Your EQ presents some basic engineering
problems for you to test your Engineering Quotient.
What's your EQ?
|
Problem
1—Suppose
you have a small package that needs to be accelerated
to 45 m/s (about 100 mph), but you have to do this on
a rail that’s just 2 m long. The package will be released
at this velocity when it reaches the end of the rail.
Assuming you can find a way to do this with constant acceleration,
how much acceleration do you need? How long does it take?
Answer
Problem
2—The package in Problem 1 weighs up to 500 g
(just over 1 lb). How much energy does it take to accelerate
it to 45 m/s? How much power?
Answer
Problem 3—An air-driven piston might be a good
way to achieve constant acceleration. If you have a piston/cylinder
with an area of 10 cm2 (about 1.55 inches squared),
how much pressure is required?
Answer
Problem
4—In a single-conversion superhet receiver, it
is often desirable to put the local oscillator frequency
above the incoming RF frequency in order to place the
image frequencies farther away from the IF passband. What
effect does this have on SSB demodulation?
Answer
Problem
5—A typical double data rate (DDR) synchronous
DRAM (SDRAM) chip allows a clock frequency range of 83
to 166 MHz. Why is it so narrow, and what benefit derives
from this?
Answer
Problem
6—What does the following
digital circuit do? The Counter box is a binary up-counter
with synchronous clear, and the Register boxes are D-type
registers with clock-enable inputs.
Answer
Problem
7—What does the following digital circuit do?
The Counter box is a binary up-counter with synchronous
clear, and the Compare boxes are magnitude comparators
whose outputs go high when their two input values are
equal.
