Formulas TQ Prep

Question 1

Circle

Answer 1

Area = Π r²
Perimeter = Πd

Question 2

Cylinder

Answer 2

Volume = Π r²h

Question 3

Rectangular

Answer 3

Volume = L x W x H
Area = L x W

Question 4

1 Kw equals

Answer 4

1.34Hp

Question 5

1Hp equals

Answer 5

0.745Kw

Question 6

FPM equals

Answer 6

CFM / Area
in Square Footage

Question 7

CFM equals

Answer 7

Area (ft²) X Velocity (fpm)

Question 8

Area (ft²) equals

Answer 8

CFM / FPM

Question 9

New RPM Formula

Answer 9

RPM x Increase % = New RPM

Question 10

What is the formula for calculating belt length?

Answer 10

OC = (Dm + Df) * 1.57 + 2L.

Dm = diameter of the driving pulley, Sm = speed of the driving pulley, Df = diameter of the driven pulley, Sf = speed of the driven pulley.

Question 11

What is the formula for calculating pulley size?

Answer 11

DM = DM x SF / Sm.

Dm = diameter of the driving pulley, Sm = speed of the driving pulley, Df = diameter of the driven pulley, Sf = speed of the driven pulley.

Question 12

What is the formula for calculating pulley speed?

Answer 12

Dm x Sm / Df = Sf.

Dm = diameter of the driving pulley, Sm = speed of the driving pulley, Df = diameter of the driven pulley, Sf = speed of the driven pulley.

Question 13

What is the formula for calculating a mitre in the field?

Answer 13

M=0xW/L

This formula is used for specific calculations related to mitres in various fields.

Question 14

What is the formula for calculating double hem allowance?

Answer 14

2W minus 1/16

W represents the width of the hem

Question 15

What formula is used for elbow heel?

Answer 15

Angle/360 x 3.14 x 2 (heel radius)

This formula calculates the arc length based on the angle and radius.

Question 16

What formula is used for elbow throat?

Answer 16

Angle/360 x 3.14 x 2 (heel radius)

Question 17

What is the formula to calculate round duct size with area?

Answer 17

R = square root of area (square inches) / 3.14

This formula is used to determine the radius of a round duct based on its cross-sectional area.

Question 18

What is the formula to find throat or heel?

Answer 18

Rx 1.57 x Degree / 90

R is the radius, and Degree refers to the angle being measured.

Question 19

How do you calculate the radius point on an ogee?

Answer 19

(offset^2 + length^2) / (4x offset)

This formula helps in determining the curvature of the ogee design.

Question 20

What is the formula for calculating the mitre angle?

Answer 20

Angle = angle of elbow / (number of PC’s x 2) - 2

PC’s refers to the number of points of curvature.

Question 21

What is the formula for the area of a triangle?

Answer 21

1/2 x Height x Base

Height (H) is the vertical height from the base to the opposite vertex, and Base is the length of the base.

Question 22

What is the formula to convert fpm to cfm at a diffuser grill or register?

Answer 22

CFM = AK x FPM

Question 23

What is the correct formula for calculating percent of design?

Answer 23

Preliminary cfm divided by Design cfm

Question 24

What is the formula for calculating BTUh after clocking the meter?

Answer 24

Btuh = (volume test dial X 3600 / time 1 revolution) calorific value

This formula is used to determine the thermal output in BTUs based on the volume of gas measured and the calorific value.

Question 25

What is the formula for calculating hourly consumption of gas?

Answer 25

Hourly consumption = size of test dial x 3600 seconds for one full revolution of test dial ## Footnote This formula helps in determining the volume of gas consumed in one hour based on the size of the test dial.

Question 26

How do you convert hourly gas consumption into BTUh?

Answer 26

BTUh = Hr consumption x Calorific value of the gas ## Footnote This conversion uses the calorific value to determine the energy content of the gas.

Question 27

What is the formula to calculate watts?

Answer 27

Volts x Amps = Watts

Question 28

What is the formula for Vertical Apex?

Answer 28

VA = VHx LD / (LD - SD) ## Footnote Where VA is Vertical Apex, VH is vertical height, LD is large diameter, and SD is small diameter.

Question 29

What does SOH stand for in trigonometry?

Answer 29

Sin = Opposite / Hypotenuse ## Footnote • Opposite is the side opposite to the angle • Adjacent is the side next to the angle • Hypotenuse is the longest side of the right triangle, opposite the right angle

Question 30

What does CAH stand for in trigonometry?

Answer 30

Cosine = Adjacent / Hypotenuse ## Footnote • Opposite is the side opposite to the angle • Adjacent is the side next to the angle • Hypotenuse is the longest side of the right triangle, opposite the right angle

Question 31

What does TOA stand for in trigonometry?

Answer 31

Tangent = Opposite / Adjacent ## Footnote • Opposite is the side opposite to the angle • Adjacent is the side next to the angle • Hypotenuse is the longest side of the right triangle, opposite the right angle

Question 32

Hypotenuse

Answer 32

A²+B²=√C² ##Footnote Make sure you square root C² to get the Hypotenuse

Question 33

Square inches of duct to square feet for formulas

Answer 33

Divide square inches by 144 ##Footnote If 20"x12=240, divide 240 by 144 240/144 which will give you the Area in ft², square footage of 1.66 ft² if the duct is 20"x12"