voltage & amps

Question 1

The size of the electric current is the rate of flow of _________.

Answer 1

electrical charge.

Question 2

Current is equal to _____ divided by time.

Answer 2

charge

Question 3

units for charge

Answer 3

coulombs

Question 4

a current of of 1 ampere =

Answer 4

1 coulomb of charge flowing per second

Question 5

An electrical insulator has_______

Answer 5

no free electrons. No charges are free to move and carry a current.

Question 6

Which charges are free to move in metals?

Answer 6

electrons

Question 7

all ______ are electrical conductors

Answer 7

metals

Question 8

The energy is transferred to the electrical components in a circuit when ____________________.

Answer 8

the charge carriers pass through them.

Question 9

what is potential difference

Answer 9

it is the energy difference per unit charge between two points in a circuit

Question 10

potential difference =

Answer 10

current x resistance

Question 11

If the resistance is increased, the current will _______

Answer 11

decrease

Question 12

If the potential difference is increased the current will _______.

Answer 12

increase.

Question 13

An electric current will increase when the number of ohms ______.

Answer 13

decrease

Question 14

On a current-voltage graph for a resistor, the slope of the graph is equal to _______.

Answer 14

1/resistance

Question 15

Resistance is a measure of how difficult it is for ______ to flow through a component.

Answer 15

current

Question 16

what is a rectifier ?

Answer 16

A component that turns an alternating current (repeatedly changes direction) into a direct current (one direction).

Question 17

_______ act as rectifiers as they block the alternating current when it changes direction.

Answer 17

Diodes

Question 18

of a rectifier, the output current is

Answer 18

direct current (DC)

Question 19

of a rectifier, the input current is

Answer 19

alternating current (AC)

Question 20

What is a thermistor ?

Answer 20

A component where resistance changes with its temperature.

Question 21

What are light dependent resistor (LDR)s .

Answer 21

A component whose resistance changes with light intensity.

Question 22

The current through an ohmic conductor (at a constant temperature) is _______.

Answer 22

directly proportional to the potential difference across the resistor.

Question 23

In an Ohmic conductor, the resistance…

Answer 23

remains constant

Question 24

R=

Answer 24

P÷I 2

Question 25

A resistor …… the flow of current…….

Answer 25

opposes ………. but does not reduce it.

Question 26

Vtotal=

Answer 26

V1+V2+V3

Question 27

Consider a circuit with two resistors of equal value connected in series. If another resistor of the same value is connected in parallel with ONE of these resistors, what will be the effect on the total resistance of the circuit?

Answer 27

the resistance decrease

Question 28

Two ohmic conductors are connected in series, with the second conductor having a larger drop in potential difference across it. What can be determined about the values of the resistances of the conductors?

Answer 28

the second conductor must have a higher resistance

Question 29

What two things will happen to a bulb that is connected in series with a thermistor, as the temperature on the thermistor changes?

Answer 29

at higher temperatures the bulb glows brighter and at high temperatures there is a higher potential difference across the bulb