Section 4

Question 1

How does a computer store binary digits?

Answer 1

In a byte

Question 2

If you have a 32 bit computer, how does it store the binary digits?

Answer 2

In 32 bit groups

64 bit is 64 bits in a group

Question 3

How do you get -1 in bits

Answer 3

2’s compliment
Let’s do 1 + -1
Flip every bit so 0001 is 1000 like below:
0001 = base10(1)
1110
After flipping bits, add 1 to answer so 1110 is 1111

0001
1111+
——-
1000 = this will equal negative
1 < there is an extra bit here, so this bit goes nowhere

This will get bad though if we add two numbers that sum is greater than 4 bits can give us.
we would have -8 - 7 to work with. Actually I think he meant 5 bit here.

first bit 0 = positive
if 1 = negative

Question 4

In a 6 bit system taking into consideration 2’s compliment, what negative number is the below:
101001

Answer 4

Last number signifies this is a negative since it is a 1, so we’ll flip and add 1
010110
1+
———–
010111 = 23
So the number is negative 23

Question 5

When is an extra bit safe in a 4 bit system?

Answer 5

if the carry bit that goes over is equal to the carry bit on the fourth bit.

If a carry bit is at the end and fits in fine, that means the non existent bit is at 0, making them different, making the calculation no good. The number can’t be represented.

Question 6

What is capacitance?

Answer 6

Ability to store charge.
Measured in Farads

Q = Charge stored in the capacitor in coulombs

C = capacitance in Farads

V is the voltage across the capacitor

So the charge is equal to farads * volts

Question 7

How do you calculate Charge stored in a capacitor?

Answer 7

Q = Charge stored in the capacitor in coulombs

C = capacitance in Farads

V is the voltage across the capacitor

So the charge is equal to farads * volts

Question 8

How do you calculate energy stored in a capacitor?

Answer 8

Fuck Energy, you don’t need this for now and calculating it is a pain in the ass for nothing at the moment.
E = Energy in joules
C = capacitance (farads)
V = voltage
1/2CV to the second power

1/2 times actually means dividing the rest by two.
10 to the power of negative six is the opposite of 10 to the power of six
We actually divide in that case
so if we were to try and figure 10 to the power of 6 we would first get 10 to the power of six and then divide one by the answer

I bring this up because if we have 10uF, that would be microfarads which 10 uF would be 1010 to the -6 power to calculate into normal farads
If you had 4uF so 410 to the negative 6 power