Circuit Components

Question 1

What are the three basic building blocks of all electric circuits

Answer 1

Resistor R, Capacitor C, and inductor L

Question 2

A capacitor has the ability to

Answer 2

store electric charge

Question 3

Charge across a capacitor is equal to

Answer 3

Q = C x Vc = capacitance (in Farads) x Voltage across the capacitor

Question 4

Energy stored in a capacitor

Answer 4

E= 0.5CVc^2

Question 5

Energy is stored in a capacitor by

Answer 5

virtue of an electric field (stored not dissipated therefore can get back)

Question 6

General form of charge stored for transient circuit

Answer 6

charge = the integral of current as a function of time with respect to time

Question 7

What is a trickle current

Answer 7

a small but constant current

Question 8

How to sum capacitors in series

Answer 8

1/Ct = 1/C1 + 1/C2 + 1/C3 + …

The charge will be equal across all in series no matter what capacitance they are

Question 9

How to sum capacitors in parallel

Answer 9

Ct = C1 + C2 + C3 + …

The charge will sum to give total charge

Question 10

What is the unit of inductane

Answer 10

Henrys H

Question 11

symbol of capactior

Answer 11

two equally long lines like a cell

Question 12

Symbol of an inductor

Answer 12

one bumpy line like a cloud

Question 13

Current through a capacitor equals

Answer 13

C * the differential of the voltage with respect to time - need change of voltage for current
C* dV/dt

Question 14

Energy stored in an inductor

Answer 14

E = 1/2 * L * I^2

Question 15

how is energy stored in an inductor

Answer 15

by virtue of a magnetic field

Question 16

Voltage across an inductor

Answer 16

L * dI/dt rate of change of current

need to be change of current to get voltage

Question 17

For inductors in series how do you calculate total inductance

Answer 17

Lt = L1 + L2 + L3 + …

Question 18

For inductors in parallel how do you calculate total inductance

Answer 18

1/Lt = 1/L1 + 1/L2 + 1/L3 + …

Question 19

if there is no change in current what is the energy stored in an inductor

Answer 19

though there is no voltage across is the is still energy stored calculated using E = 1/2 * L*I^2

Question 20

if the current of 4A falls to zero in 10ms what is the change of current and therefore the voltage across an inductor of 0.5H

Answer 20

dI/dt = 4/10*10-3
V = L*dI/dt