Note: The sheet that you will be given is not annotated with what the equation is used for but just gives you the equation.
Note : Manipulation of the equation to find the missing item may be needed in any of the following. The mathematical notation is being used where two letter together means multiplied eg. P = VI is the same as P = V x I |
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Equation(s) |
To calculate ???? |
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where |
R(total) = R1 + R2 + R3 |
To find the total resistance in series | Click here |
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To find the total resistance in parallel | Click here |
P = VI, V = IR |
To calculate power, voltage, current, or resistance given any other two. These have been seen in the Foundation or Intermediate level courses | Click here |
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To calculate the voltageout relative to the voltagein with regards to a potential divider where R1 and R2 represent the resistance value either side of the centre. | Click here |
P = V2 / R, P = I2R |
As above but this set are new to the Advanced level. | |
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To calculate the RMS of a voltage which gives the same heating effect as a direct current of the same numeric value. | |
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To calculate the effective total capacitance of a number capacitors linked in series | Click here |
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To calculate the effective total capacitance of capacitors linked in parallel, | Click here |
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To calculate the value of a capacitor from area and separation of the plates, permittivity of dielectrics | |
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To calculate the effective total inductance of a number inductors linked in series | |
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To calculate the effective total inductance of a number inductors linked in parallel | Click here |
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To calculate the inductive reactance for a known frequency and known inductance. | Click here |
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To calculate the impedance from a combination of resistance and reactance. | Click here |
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The supply voltage Vtotal (VT) is thus the sum of the vectors through the Resistor VR and Capacitor VC (or Inductor) | Click here |
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To calculate the capacitive reactance for a known frequency and known capacitance. | Click here |
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To calculate the frequency of resonant a tuned circuit knowing the value of the inductance and capacitance. | Click here |
T = 1 / f and f = 1 / T |
To calculate the time period of a sine wave at a particular frequency or the frequency knowing the time period. | |
T=CR |
To calculate the charging and discharging of a capacitor in a CR circuit | |
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To calculate the Q factor ( quality Factor) knowing the value of the frequency, inductance and capacitance. | |
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Calculation of the Q of a tuned circuit, knowing the centre frequency, and the upper and lower frequencies where the half power points are noted. | Click here |
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To calculate the dynamic resistance RD knowing the value of the resistance, inductance and capacitance | Click here |
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The relationship between Q and Frequency, Capacitance, and Dynamic Resistance | Click here |
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Formulas relating transformer primary Np and secondary Ns turns to primary and secondary potential differences Vs Vp and currents Ip Is | Click here |
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Formula relating transformer primary Np and secondary Ns turns to primary and secondary impedances Zp Zs | |
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The two equation
mean the same hfe = ![]() |
Click here |
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To calculate the frequency step from the crystal frequency. | Click here |
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To calculate the out going frequency from a frequency synthesizer. | Click here |
c = 3 x 108 m/s |
speed of light But
this might be better remembered as
c = 300 x 106 m/s |
Click here |
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The equations relating to decibel power ratios. | Click here |
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The calculation of standing wave ratio (SWR) by reference to VFORWARD and VREVERSE | Click here |
v = fλ c = fλ Please note that sometimes v is used for the speed of light and at other times c. |
From the speed of the velocity of light the wavelength can be determined knowing the frequency or the frequency knowing the wavelength. This was first introduced to you in chart form in the Foundation Licence course. | Click here |
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The equations relating to decibel and voltage ratios. | Click here |
Z02 = Zin X Zout |
The formula relating Z0 = the impedance of the quarter-wave length of feeder matching line to the impedance of the antenna Zin and the impedance of the antenna Zout from the matching line | Click here |
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To calculate the field strength in volts /m given the ERP and distance from the antenna. | Click here |
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To calculate return loss | Click here |
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Bw is the bandwidth requirement in relation to Af is the highest modulating frequency and Δf is the carrier peak deviation frequency | Click here |
erp = power x gain (linear) |
To calculate the Effective Radiated Power (erp) from an antenna | Used in the Intermediate course |
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To calculate gain of Yagi over a dipole | Click here |