Which letter is commonly used to denote resistance in circuit equations?

Which letter is commonly used to denote resistance in circuit equations?

• A. R
• B. V
• C. I
• D. P

Answer: (A)

R is used for resistance because the symbol comes from the word resistance itself. In circuit equations, Ohm’s law is V = IR, which shows how voltage, current, and resistance relate to one another. The unit of resistance is the ohm (Ω). Other quantities have their own symbols: voltage is denoted by V, current by I, and power by P, with P often written as P = VI or P = I^2R. This consistent use of R for resistance keeps circuit equations clear and standardized.

R is used for resistance because the symbol comes from the word resistance itself. In circuit equations, Ohm’s law is V = IR, which shows how voltage, current, and resistance relate to one another. The unit of resistance is the ohm (Ω). Other quantities have their own symbols: voltage is denoted by V, current by I, and power by P, with P often written as P = VI or P = I^2R. This consistent use of R for resistance keeps circuit equations clear and standardized.