State Ohm's law and name the symbols.

State Ohm's law and name the symbols.

• A. E = mc^2; E is energy
• B. F = m a; F is force
• C. V = IR; V is voltage, I is current, R is resistance
• D. P = VI; P is power

Answer: (C)

Ohm’s law shows how voltage, current and resistance connect in a circuit. It says the voltage across a component equals the current through it times its resistance. The symbols are V for voltage, I for current, and R for resistance, written as V = IR. This means if you know any two of the quantities, you can find the third. For example, with a fixed resistance of 5 ohms, a current of 2 amperes gives a voltage of 10 volts (V = IR = 5 × 2). If you double the current through the same resistor, the voltage across it doubles. If the resistance changes while the current stays the same, the voltage changes proportionally as well. The other formulas shown relate to different ideas (energy-mass equivalence, Newton’s second law, or power) and don’t express the essential voltage–current–resistance relationship described by Ohm’s law.

Ohm’s law shows how voltage, current and resistance connect in a circuit. It says the voltage across a component equals the current through it times its resistance. The symbols are V for voltage, I for current, and R for resistance, written as V = IR. This means if you know any two of the quantities, you can find the third. For example, with a fixed resistance of 5 ohms, a current of 2 amperes gives a voltage of 10 volts (V = IR = 5 × 2). If you double the current through the same resistor, the voltage across it doubles. If the resistance changes while the current stays the same, the voltage changes proportionally as well. The other formulas shown relate to different ideas (energy-mass equivalence, Newton’s second law, or power) and don’t express the essential voltage–current–resistance relationship described by Ohm’s law.