Moving Charges And Magnetism (VSAQs)
Physics-2 | 7. Moving Charges and Magnetism – VSAQs:
Welcome to VSAQs in Chapter 7: Moving Charges and Magnetism. This page includes the important FAQs for Very Short Answer Questions. Answers are provided in simple English and follow the exam format. This approach helps you concentrate on essential points and achieve top marks in your final exams.
VSAQ-1 : What is the importance of Oersted’s experiment?
Oersted’s experiment is important because it demonstrated the connection between electricity and magnetism. It revealed that an electric current flowing through a conductor creates a magnetic field around it. This discovery laid the foundation for electromagnetism, a fundamental concept in physics, and contributed to the development of modern technologies.
VSAQ-2 : Distinguish between ammeter and voltmeter.
An ammeter measures current in a circuit and is connected in series with the circuit components. It has low resistance and is calibrated in amperes (A).
A voltmeter measures voltage or potential difference in a circuit and is connected in parallel with the circuit components. It has high resistance and is calibrated in volts (V).
VSAQ-3 : What is the principle of a moving coil galvanometer?
The principle of a moving coil galvanometer is based on the interaction between a current-carrying coil and an external magnetic field. When a current flows through the coil, it experiences a magnetic torque, resulting in coil deflection, with the angle of deflection being proportional to the current magnitude. This deflection facilitates accurate current measurement in the circuit.
VSAQ-4 : How do you convert a moving coil galvanometer into an ammeter?
To convert a moving coil galvanometer into an ammeter, a low resistance shunt is connected in parallel to the galvanometer. The shunt’s value is adjusted to ensure that most of the current flows through it, diverting a significant portion of the current away from the galvanometer. This arrangement allows the galvanometer to measure heavy currents without getting fully deflected. By effectively bypassing the majority of the current through the shunt, the galvanometer measures only a small fraction of the total current, making it suitable for measuring larger currents accurately. This conversion transforms the galvanometer into an ammeter, capable of precisely measuring current.
VSAQ-5 : How do you convert a moving coil galvanometer into an voltmeter?
To convert a moving coil galvanometer into a voltmeter, you connect a high resistance called the multiplier or series resistance in series with the galvanometer. This added resistance increases the overall resistance of the galvanometer, enabling it to measure high voltages without causing significant deflection. The series resistance limits the current flowing through the galvanometer, ensuring accurate voltage measurements without drawing excessive current from the circuit. This conversion effectively transforms the galvanometer into a voltmeter suitable for measuring high voltages.
VSAQ-6 : A circular coil of radius r having N turns carries a current “i”. What is its magnetic moment?
The magnetic moment (μ) of a circular coil with radius r and carrying a current I is given by the formula:
$$\mu = N \cdot I \cdot A$$
Where
- μ is the magnetic moment.
- N is the number of turns of the coil.
- I is the current flowing through the coil.
- A is the area enclosed by the coil.
For a circular coil, the area A can be calculated as:
$$A = \pi \cdot r^2$$
Now, you can plug in the values:
$$\mu = N \cdot I \cdot \pi \cdot r^2$$
So, the magnetic moment (μ) of the circular coil is $$N \cdot I \cdot \pi \cdot r^2$$