What is the function of a galvanometer, ammeter, and voltmeter? How are they connected in circuits?

A galvanometer, ammeter, and voltmeter are all types of instruments used to measure electrical quantities in a circuit. Each has a specific function and is connected in a unique way to the circuit.

1. Galvanometer:

  • Function: A galvanometer is used to detect and measure small amounts of current in a circuit. It can also be used to measure the potential difference (voltage) across two points in a circuit.
  • Connection: It is typically connected in series when measuring current. If used for measuring voltage, it is connected in parallel, though it can only handle small voltages directly. Galvanometers are often used to calibrate other instruments like ammeters and voltmeters.

2. Ammeter:

  • Function: An ammeter is used to measure the current flowing through a circuit. It has a very low internal resistance to minimize its impact on the circuit’s current.
  • Connection: An ammeter is connected in series with the circuit elements. This allows the current to flow through the ammeter, enabling it to measure the amount of current in the circuit.

3. Voltmeter:

  • Function: A voltmeter measures the potential difference (voltage) between two points in a circuit. It has a very high internal resistance, ensuring that it does not draw significant current from the circuit.
  • Connection: A voltmeter is connected in parallel across the two points where the voltage is to be measured. This ensures that it measures the potential difference without significantly affecting the current flow in the circuit.

Summary of Connections:

  • Galvanometer: In series (for current) or parallel (for voltage), depending on usage.
  • Ammeter: In series with the circuit.
  • Voltmeter: In parallel with the two points where the voltage is to be measured.

These instruments are essential for analyzing and understanding the behavior of electrical circuits.

Related Questions:

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  2. Two electric bulbs marked 100 W, 220 V and 200 W, 220 V have tungsten filaments of the same length. Which bulb has a thicker filament?
  3. Show that Volt-Ampere is equal to Watt (SI unit of power).
  4. Define and explain the term electric current. What is the difference between electronic current and conventional current?
  5. How can you differentiate between emf and potential difference? What do you mean by emf? Is it really a force? Explain
  6. Explain Ohm’s Law. What are its limitations? Differentiate between ohmic and non-ohmic conductors.
  7. Analyze IV characteristic graphs for a metallic conductor, an incandescent bulb, and a thermistor to determine ohmic and non-ohmic behavior.
  8. Define resistance and its unit. What is the cause of resistance? On what factors does the resistance of a metallic conductor depend?
  9. How are resistances connected in series? What are their characteristics? Derive the formula for equivalent resistance.
  10. How are resistances connected in parallel? What are their characteristics? Derive the formula for equivalent resistance.
  11. In a circuit, three bulbs are connected in series and in another circuit, three bulbs are connected in parallel. The magnitude of the emf source for both circuits is the same. How can you explain the difference in brightness of bulbs in both circuits?
  12. State and prove Joule’s law of heating.
  13. What is electric power? Derive its different formulae.
  14. Define kilowatt-hour (kWh). What is its relation with joule? How can you calculate energy in kWh by a formula?
  15. 12. Differentiate between direct current (DC) and alternating current (AC). Define the following terms for AC: (i) Cycle, (ii) Time period, (iii) Frequency.
  16. Can current flow through a circuit without potential difference? Explain.
  17. Can current flow through a circuit without potential difference? Explain.
  18. What is the resistance across an open switch and a closed switch of a circuit?
  19. Why is a bird sitting on a high-voltage transmission line not electrocuted? Why does it get electrocuted when it touches another wire?
  20. 5. How can you arrange five resistances to form a circuit with resistance smaller than any given resistance?