D.C Circuits

Question 1

Why will electrons not change speed while losing resistance

Answer 1

They receive more energy from the electrons behind them

Question 2

Define what is D.C

Answer 2

Direct Current

Question 3

What is Kirchoff’s first law current

Answer 3

At a junction, the sum of currents flowing into the junction must equal to the sum of current flowing out.

Question 4

How does current split in a junction

Answer 4

In a ratio, if 1 has 10 resistance and other has 20 resistance its split 1:2

Question 5

If the current flowing through a circuit is 1A and A is 10Ω, B is 20Ω and C is 40Ω. How much current does A receive

Answer 5

4/7 or 0.76 because it gets 2x as much as B or 4x as much as C because of ratio of resistance

Question 6

If the current flowing through a circuit is 1A and A is 10Ω, B is 20Ω and C is 40Ω. How much current does B receive

Answer 6

2/7A

Question 7

What is Kirchoff’s Voltage Law

Answer 7

The algebraic sum of voltages around a closed circuit path must be 0

Question 8

What is the equation of Kirchhoff’s voltage law

Answer 8

ΣV = V1+V2+V3+V4+…

Question 9

If V1 = 4, V2 = 4 and V3 = 2, what is the Voltage of the battery

Answer 9

10V

Question 10

Define a circuit in series

Answer 10

One continuous lap

Question 11

Parallel paths must have the same p.d True or False

Answer 11

True

Question 12

What is V=IR

Answer 12

Ohms Law

Question 13

How dos resistance add up in series

Answer 13

R1 + R2 + R3…

Question 14

How does resistance add up in parallel

Answer 14

1/R1 + 1/R2 + 1/R3 = 1/Rt then you flip it

Question 15

What is a potential Divider

Answer 15

It involves two or more resistors in series and is designed to do 3 things
1) Provide a fixe p.d anywhere between 0 and source emf
2) Provide a variable p.d
3) Provide a p.d that varies with physical attribute like temp

Question 16

What are the 3 things a Potential Divider is used for

Answer 16

1) Provide a fixe p.d anywhere between 0 and source emf
2) Provide a variable p.d
3) Provide a p.d that varies with physical attribute like temp

Question 17

What is a sensor

Answer 17

Electrical component that is designed to respond to external stimuli

Question 18

What is a semiconductor

Answer 18

Material that switch from behaving like an insulator to a conductor

Question 19

Do Semiconductors start off with a lot of free charge carrier

Answer 19

False, they produce them as they absorb energy

Question 20

What are thermistors

Answer 20

Thermistors change their resistance based on the temperature

Question 21

Explain a Negative Temperature coefficient in a thermistor

Answer 21

The Semiconductor has a NTC, where if the temperature increases, the resistance decreases

Question 22

In an LDR when Light increases does the resistance increase or decrease

Answer 22

Decrease

Question 23

Can sensors and Ohm’s law work together

Answer 23

Yes as at a fixed temperature the resistance will be constant

Question 24

What is EMF measured in

Answer 24

Volts

Question 25

What is Electromotive Force

Answer 25

The energy gained per coulomb

Question 26

Do all sources of EMF have a resistance

Answer 26

Yes, they have an internal resistance

Question 27

What does internal resistance cause

Answer 27

A loss in voltage

Question 28

What is the equation for Terminal PD in terms of internal resistance

Answer 28

V = E - Ir

Question 29

Explain every letter in V = E - Ir

Answer 29

V= Terminal p.d E = EMF I = Current r = Internal Resistance

Question 30

What is the difference between EMF and Terminal PD

Answer 30

EMF is like the perfect scenario which is the maximum voltage when no current is flowing Terminal p.d is the realistic version which will be less than EMF because it accounts for Internal Resistance