Chapter 3: Magnetism and Magnetic Effects of Electric Current — Online MCQ Test
PHYSICS · CLASS 12th · Tamil Nadu State Board
Practice Chapter 3: Magnetism and Magnetic Effects of Electric Current with a free chapter-wise online MCQ test.
This chapter covers: This chapter details magnetic properties Biot-Savart law and Ampere circuital law. Students explore moving coil galvanometers magnetic field calculations cyclotron mechanics and ea....
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Chapter 3: Magnetism and Magnetic Effects of Electric Current — Important Questions & Answers
Which law gives the magnetic field produced by a small current element?
- A. Coulomb's law
- B. Biot-Savart law
- C. Faraday's law
- D. Lenz's law
Answer: B. Biot-Savart law
Biot-Savart law is used to calculate the magnetic field due to a current-carrying conductor element.
Biot-Savart law is used to calculate the magnetic field due to a current-carrying conductor element.
The SI unit of magnetic field is
- A. tesla
- B. weber
- C. ampere
- D. newton
Answer: A. tesla
The tesla (T) is the SI unit of magnetic flux density or magnetic field.
The tesla (T) is the SI unit of magnetic flux density or magnetic field.
For a long straight current-carrying conductor, the magnetic field lines are
- A. straight lines parallel to the wire
- B. concentric circles around the wire
- C. radial lines outward from the wire
- D. elliptical paths around the wire
Answer: B. concentric circles around the wire
The magnetic field around a long straight wire forms concentric circles centered on the wire.
The magnetic field around a long straight wire forms concentric circles centered on the wire.
The radius of the path of a charged particle in a cyclotron depends on
- A. only the charge of the particle
- B. only the magnetic field
- C. velocity of the particle and magnetic field
- D. time period of the particle only
Answer: C. velocity of the particle and magnetic field
The radius is given by r = mv/qB, so it depends on velocity, mass, charge, and magnetic field.
The radius is given by r = mv/qB, so it depends on velocity, mass, charge, and magnetic field.
In a moving coil galvanometer, the current sensitivity is proportional to
- A. number of turns in the coil
- B. square of the coil resistance
- C. inverse of magnetic field strength
- D. mass of the coil
Answer: A. number of turns in the coil
Current sensitivity increases with the number of turns because torque increases with more turns.
Current sensitivity increases with the number of turns because torque increases with more turns.