simple circuit

Examples of simple circuit in the following topics:

• Current and Voltage Measurements in Circuits

  • To understand how to measure current and voltage in a circuit, you must also have a general understanding of how a circuit works and how its electrical measurements are related.
  • A simple circuit consists of a voltage source and a resistor and can be schematically represented as in .
  • Using this equation, we can calculate the current, voltage, or resistance in a given circuit.
  • For example, if we had a 1.5V battery that was connected in a closed circuit to a lightbulb with a resistance of 5Ω, what is the current flowing through the circuit?
  • A simple electric circuit made up of a voltage source and a resistor

• Different Types of Currents

  • A resistive circuit is a circuit containing only resistors and ideal current and voltage sources.
  • If a capacitor or inductor is added to a DC circuit, the resulting circuit is not, strictly speaking, a DC circuit.
  • This solution gives the circuit voltages and currents when the circuit is in DC steady state.
  • A simple DC circuit is illustrated in .
  • A simple DC circuit with a voltage source (V) and resistor (R).

• Ohm's Law

  • Ohm's Law states that current is proportional to voltage; circuits are ohmic if they obey the relation V=IR.
  • An object that has simple resistance is called a resistor, even if its resistance is small .
  • In a simple circuit (one with a single simple resistor), the voltage supplied by the source equals the voltage drop across the resistor, since E=qΔV, and the same q flows through each.
  • A simple electric circuit in which a closed path for current to flow is supplied by conductors (usually metal wires) connecting a load to the terminals of a battery, represented by the red parallel lines.
  • The voltage drop across a resistor in a simple circuit equals the voltage output of the battery.

• Overview of Electric Current

  • In electric circuits, this charge is often carried by moving electrons in a wire.
  • The figure above shows a simple circuit and the standard schematic representation of a battery, conducting path, and load (a resistor).
  • Schematics are very useful in visualizing the main features of a circuit.
  • (a) A simple electric circuit.
  • The schematic represents a wide variety of similar circuits.

• Resisitors in Series

  • Most circuits have more than one component, called a resistor, that limits the flow of charge in the circuit.
  • The total resistance in the circuit is equal to the sum of the individual resistances, since the current has to pass through each resistor in sequence through the circuit.
  • Therefore, for every circuit with N number of resistors connected in series:
  • In a simple circuit consisting of one 1.5V battery and one light bulb, the light bulb would have a voltage drop of 1.5V across it.
  • A brief introduction to series circuit and series circuit analysis, including Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL).

• The Loop Rule

  • Mathematically, Kirchhoff's loop rule can be represented as the sum of voltages in a circuit, which is equated with zero:
  • Here, Vk is the voltage across element k, and n is the total number of elements in the closed loop circuit.
  • An illustration of such a circuit is shown in .
  • illustrates the changes in potential in a simple series circuit loop.
  • (a) In this standard schematic of a simple series circuit, the emf supplies 18 V, which is reduced to zero by the resistances, with 1 V across the internal resistance, and 12 V and 5 V across the two load resistances, for a total of 18 V.

• Resistors in AC Circuits

  • It is the steady state of a constant-voltage circuit.
  • If the source varies periodically, particularly sinusoidally, the circuit is known as an alternating-current circuit.
  • Ohm's law applies to AC circuits as well as to DC circuits.
  • The voltage and current are sinusoidal and are in phase for a simple resistance circuit.
  • Apply Ohm's law to determine current and voltage in an AC circuit

• Safety Precautions in the Household

  • In practice, a simple AC circuit with no safety features is not how power is distributed .
  • The first safety feature is the familiar circuit breaker (or fuse) that prevents thermal overload.
  • The neutral wire is the return path for the current to follow in order to complete the circuit.
  • A schematic of a simple AC circuit with a voltage source and a single appliance represented by the resistance R.
  • Identify major risks associated with the electrical circuits and strategies to mitigate those risks

• Resistors and Capacitors in Series

  • An RC circuit is one containing a resistor R and a capacitor C.
  • In this Atom, we will study how a series RC circuit behaves when connected to a DC voltage source.
  • Fig 1 shows a simple RC circuit that employs a DC voltage source.
  • We define the time constant τ for an RC circuit as $\tau = RC$. τ shows how quickly the circuit charges or discharges.
  • (a) An RC circuit with an initially uncharged capacitor.

• Humans and Electric Hazards

  • A classic example of this is the short circuit, shown in .
  • A short circuit is a low-resistance path between terminals of a voltage source.
  • A thermal hazard can be created even when a short circuit is not present if the wires in a circuit are overloaded with too much current.
  • Very high voltage (over about 600 volts): This poses an additional risk beyond the simple ability of high voltage to cause high current at a fixed resistance.
  • (b) A schematic of the short circuit.