Interactive EX308 Formula Sheet
Click any formula to see calculator keys, meanings of variables and formula transpositions
Ohm's Law   \( V = IR \)
Power   \( P = V \times I \)
Series   \( R_T = R_1 + R_2 + R_3 \)
Parallel   \( \frac{1}{R_T} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} \)
Potential divider   \( V_{out} = V_{in} \frac{R_2}{R_1 + R_2} \)
Series   \( \frac{1}{C_T} = \frac{1}{C_1} + \frac{1}{C_2} + \frac{1}{C_3} \)
Parallel   \( C_T = C_1 + C_2 + C_3 \)
Series   \( L_T = L_1 + L_2 + L_3 \)
Parallel   \( \frac{1}{L_T} = \frac{1}{L_1} + \frac{1}{L_2} \)
AC   \( V_{rms} = \frac{V_{peak}}{\sqrt{2}} \)
AC   \( t = \frac{1}{f} \)     \( f = \frac{1}{t} \)
Inductor   \( X_L = 2{\pi}fL \)
Capacitor   \( X_C = \frac{1}{2{\pi}fC} \)
Tuned curcuit   \( Q = \frac{f_C}{f_U-f_L} = \frac{centre frequency}{bandwidth}\)
Transformer   \( V_s = V_p\frac{N_s}{N_p} \)
Transformer   \( I_p = I_s\frac{N_s}{N_p} \)
Transistor   \( I_c={\beta}I_B \)
Velocity of radio waves in free space
\( v = \) 3x108 m/s \( = \) 300,000,000 m/s
Frequency & wavelength    \( v=f{\lambda} \)
Antenna   \( erp = power \times gain \,(linear) \)