Unit 202

Question 0

I relates to what?

Answer 0

Current in Amperes

Question 1

Q relates to what?

Answer 1

Charge transferred in Coulombs.

Question 2

t relates to what?

Answer 2

Time in seconds

Question 3

What is the formula…

Q=It, or I=Q/t

Answer 3

Q=It
How many Coulombs per time period (t) at a particular current (I)

I=Qt
What current is produces when an amount of Coulombs move through a conductor in a specified amount of time (t)

Question 4

What is a Coulomb?

Answer 4

1 coulomb is 6.7 times 10 to the power of 18 electrons moving through a conductor.

1A is equal to 1Q per second.

Question 5

How many Coulombs if there is a charge of 3A over 32 seconds.

Answer 5

Q=It

I = 3
T=32

3x32=96C

Question 6

What charge is produced by 834 Coulombs in 2 minutes?

Answer 6

I=Q/t

Q=834
t=120

834/120=41.7A

Question 7

What is the definition of EMF (Electro Motive Force)

Answer 7

The number of Joules (J) of work require to move 1 C of electricity around a circuit.

This unit inis referred to as a Volt (V)

1V = 1 Joule/ 1 Coulomb

Question 8

Q=It
W=QxV

If a battery of 12V gives a current of 5A for 10 minutes the amount of energy provided over the 10 minute period is?

Answer 8

W=QxV
Q=It = 5x (10x60)C
Q=3000C
W=QxV = 3000x12
W= 36000 J or 3.6 kJ

Question 9

What are the three effects of electrical current?

Answer 9

Thermal (Heating)
Chemical
Magnetism

Question 10

What are the quantity and unit symbols for current?

Answer 10

Quantity = I
Unit = A

Question 11

What are the quantity and unit symbols for length?

Answer 11

Quantity = l (lower case L)
Unit = m

Question 12

What are the quantity and unit symbols for luminous intensity?

Answer 12

Quantity = I (upper case i)
Unit = cd

Question 13

What are the quantity and unit symbols for mass?

Answer 13

Quantity = m
Unit = kg

Question 14

What are the quantity and unit symbols for temperature?

Answer 14

Quantity = T
Unit = K (kelvin)

Question 15

What are the quantity and unit symbols for time?

Answer 15

Quantity = t
Unit = s (second)

Question 16

What are the quantity and unit symbols for area?

Answer 16

Quantity = A
Unit = m2 (metres squared)

Question 17

What are the quantity and unit symbols for capacitance?

Answer 17

Quantity = C
Unit = F (farad)

Question 18

What are the quantity and unit symbols for charge?

Answer 18

Quantity = Q
Unit = C (coulomb)

Question 19

What are the quantity and unit symbols for energy (work)?

Answer 19

Quantity = W (watt)
Unit = J (joule)

Question 20

What are the quantity and unit symbols for force?

Answer 20

Quantity = F
Unit = N (Newton)

Question 21

What are the quantity and unit symbols for frequency?

Answer 21

Quantity = f
Unit = H (hertz)

Question 22

What are the quantity and unit symbols for impedance?

Answer 22

Quantity =Z

Unit = ohm

Question 23

What are the quantity and unit symbols for inductance?

Answer 23

Quantity = L
Unit = H (Henry)

Question 24

What are the quantity and unit symbols for magnetic flux?

Answer 24

``` Quantity = phi symbol ( like an o with an I through it) Unit = Wb (weber) ```

Question 25

What are the quantity and unit symbols for magnetic-flux density?

Answer 25

Quantity =B | Unit = T (tesla)

Question 26

What are the quantity and unit symbols for potential difference?

Answer 26

``` Quantity = V Unit V (volt) ```

Question 27

What are the quantity and unit symbols for power?

Answer 27

``` Quantity = P Unit = W (watt) ```

Question 28

What are the quantity and unit symbols for reactance?

Answer 28

``` Quantity = X Unit = ohm ```

Question 29

What are the quantity and unit symbols for resistance?

Answer 29

``` Quantity = R Unit = ohm ```

Question 30

What are the quantity and unit symbols for resistive Ty?

Answer 30

``` Quantity = rho symbol (p) Unit = ohm-metre ```

Question 31

What is the power of 10 used for tera (T)?

Answer 31

12

Question 32

What is the power of 10 used for giga (G)?

Answer 32

9

Question 33

What is the power of 10 used for mega (M)?

Answer 33

6

Question 34

What is the power of 10 used for kilo (k)?

Answer 34

3

Question 35

What is the power of 10 used for hecto (h)?

Answer 35

2

Question 36

What is the power of 10 used for deka (da)?

Answer 36

1

Question 37

What is the power of 10 used for deci (d)?

Answer 37

-1

Question 38

What is the power of 10 used for centi (c)?

Answer 38

-2

Question 39

What is the power of 10 used for milli (m)?

Answer 39

-3

Question 40

What is the power of 10 used for micro (u micro symbol)?

Answer 40

-6

Question 41

What is the power of 10 used for nano (n)?

Answer 41

-9

Question 42

What is the power of 10 used for pico (p)?

Answer 42

-12

Question 43

Sin=?

Answer 43

Opposite/hypotenuse

Question 44

Cos=?

Answer 44

Adjacent/hypotenuse

Question 45

Tan=?

Answer 45

Opposite/adjacent

Question 46

Given Sin0=o/h, if the opposite = 7 and the angle is 35 degrees, what is the length of the hypotenuse?

Answer 46

Sin0=o/h Transpose to h=o/Sin0 h=7/sin35 h= 12.2m

Question 47

Given that Cos0=a/h, if the angle is 50 degrees and the hypotenuse is 18m, what is the length of the adjacent?

Answer 47

Cos0=a/h Transpose... a=cos0 x h a=cos50 x 18 Adjacent = 11.57m

Question 48

Given that Tan0=o/a, if the adjacent is 20m and the angle is 70 degrees, what is the length of the hypotenuse?

Answer 48

Tan0=o/a Transpose... O=tan0xa Tan70x20=54.9m

Question 49

The specific resistance of a material is represented by which symbol?

Answer 49

rho (p)

Question 50

Given R=p(rho)l/A | Calculate the resistance of 1000m of 16mm squared cable where p (rho) = 0.0172 micro ohms per metre.

Answer 50

R=1.075

Question 51

What is the formula to work out resistivity?

Answer 51

R=p(rho)l/A

Question 52

Given that R(t1) = R(t2)x(1+a(alpha)T). If the resistance of 100m of 2.5mm squared copper cable 0.5375 ohms at 20 degrees C, and the coefficient for copper at 20 degrees C is 0.00396 ohms, it's resistance at 50 degrees C is?

Answer 52

0.60 ohms