Useful answers.
Understand the working.
Calculators and worksheets for the subjects you study and the problems you meet in practice. Work through an example, try your own values, then test the same ideas in exam practice.
Balanced three phase calculator
Separate line and phase quantities for star and delta connections in electrical theory practice. Use RMS line measurements when calculating total balanced power.
Open tool →FREE TOOLSeries RLC impedance calculator
Keep inductive and capacitive reactance signs visible in a series circuit. Read the impedance phasor before interpreting its magnitude and phase angle.
Open tool →FREE TOOLIdeal transformer calculator
Relate winding turns to voltage and inverse current ratios. State the known winding side so the transformation direction is unambiguous.
Open tool →FREE TOOLPower factor correction calculator
Calculate reactive compensation for an improved lagging power factor. Specify capacitor connection before converting total reactive power to capacitance per branch.
Open tool →FREE TOOLMotor speed and slip calculator
Link supply frequency and pole count to synchronous speed, then interpret rotor slip. Recognise supersynchronous operation from the sign of the calculated slip.
Open tool →Tools that connect the calculation to the concept
Each tool shows its method, units and assumptions, together with two worked examples. Example values are for learning; replace them with your own measurements or documented inputs. The related study links take you to the matching certification topic on Denken Exam.
Worksheets run in your browser. We do not send entered measurements or report text to a calculation service. Where export is available, you choose when to save the file locally.
Check the boundary of the answer
A useful result starts with the right inputs and an appropriate method. These tools explain what is calculated and what the method leaves out. User-supplied criteria remain identified as supplied criteria; a calculation does not automatically approve equipment, certify an inspection or establish regulatory compliance.