Deck 2: Sensors and Actuators

Question 1

A consumer TV with 4K resolution has a screen that contains 3840 by 2160 array of pixels.Each
RGB LED can shine at 256 intensity levels.The number of bits required to display a complete
image equals ______.?

Answer 1

Question 2

An IR autofocus system has emitter and detector apertures separated by 1cm and modeled as
pin holes.The light reflected from an object at range r casts a spot that is detected at a
displacement of 0.1mm from the detector axis.The detector lies 0.5cm behind the pin hole.The
value of r equals _____

Answer 2

Question 3

A scientific calculator has 5 rows and 9 columns.How many bits required for addressing
assuming separate row and column addresses?

Answer 3

Question 4

Your audio system uses 24 bits to encode audio waveform samples.How many different levels
can be encoded using the approximation

Question 5

Your smartphone has an 8 Megapixel camera with each pixel containing red, green,
and blue sensors.If each sensor produces 256 levels of intensity, how many bits are required to
encode an image?

Question 6

An underwater sonar detects the echo from an object at 100m range.The TOF equals ___ ( x.xx
s).

Question 7

An air sonar detects the echo TOF from an object to be 10 milliseconds.The object range equals
___

Question 8

Finger swipe speed.Your smartphone square touch screen measures 10 cm x 10 cm and
implements a 100 x 100 switch array.A horizontal finger swipe must activate at least 25
columns in any particular row within 0.5 seconds.What is the minimum speed (m/s) that your
finger must travel to form a valid finger swipe?

Question 9

Your smartphone touch screen implements a switch array.What is the minimum
number of bits that defines the address of each switch assuming separate row and column
addresses?