Introduction
Electric current important questions and answers provide a comprehensive understanding of this fundamental physics concept. Explore key queries to strengthen your knowledge.
Electric Current Important Questions and Answers
One-Liner Questions
- What is electric current?
- What is the SI unit of electric current?
- How is electric current measured?
- What causes electric current in a conductor?
- What is the direction of conventional current flow?
- What is Ohm’s Law?
- What are the types of electric current?
- What is the difference between AC and DC?
- What is resistance in an electric circuit?
- What factors affect the resistance of a conductor?
- What is the role of a battery in an electric circuit?
- What is the relationship between voltage, current, and resistance?
- What happens when resistances are connected in series?
- What happens when resistances are connected in parallel?
- What is the heating effect of electric current?
- What is Joule’s Law of Heating?
- What is the difference between open and closed circuits?
- What is an ammeter used for?
- What is a voltmeter used for?
- What is the function of a fuse in an electrical circuit?
Answers
- Electric current is the rate of flow of electric charge through a conductor.
- The SI unit of electric current is Ampere (A).
- Electric current is measured using an ammeter.
- Electric current in a conductor is caused by the movement of free electrons under the influence of an electric field.
- Conventional current flows from the positive terminal to the negative terminal of a battery.
- Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage across it, provided the temperature remains constant.
- The two main types of electric current are Alternating Current (AC) and Direct Current (DC).
- AC changes its direction periodically, while DC flows in one direction only.
- Resistance is the opposition offered by a conductor to the flow of electric current.
- Factors affecting resistance include length, cross-sectional area, material, and temperature of the conductor.
- A battery provides the potential difference required to drive electric current through a circuit.
- Voltage (V) = Current (I) × Resistance (R), as per Ohm’s Law.
- In series connection, total resistance equals the sum of individual resistances, and current remains the same.
- In parallel connection, the reciprocal of total resistance equals the sum of reciprocals of individual resistances, and voltage remains the same.
- The heating effect of electric current occurs due to the collision of electrons with atoms in the conductor, producing heat.
- Joule’s Law of Heating states that heat produced is proportional to the square of the current, resistance, and time.
- An open circuit has a break in the path, so no current flows, while a closed circuit allows current to flow.
- An ammeter is used to measure electric current in a circuit.
- A voltmeter is used to measure the potential difference across two points in a circuit.
- A fuse protects the circuit by melting and breaking the flow of current during overloads or short circuits.
Key Takeaways
- Electric current is the flow of electric charge, measured in Amperes.
- Ohm’s Law establishes the relationship between voltage, current, and resistance.
- AC and DC differ in their direction of flow and applications.
- Resistance depends on the conductor’s length, area, material, and temperature.
- Series and parallel connections have different effects on current and voltage distribution.
- The heating effect of current is utilized in appliances like heaters and bulbs.
- Fuses and circuit breakers protect electrical devices from excessive current.
- Ammeters measure current, while voltmeters measure voltage.
- Batteries provide the necessary potential difference to drive electric current.
- Understanding electric current is essential for studying advanced electrical concepts.