Expert Physics Tutoring

MS1:

- The process in which a changing magnetic field induces an electromotive force (EMF) or electric current in a conductor (1)

MS2:

- A generator rotates a coil in a magnetic field, changing the magnetic flux through the coil (1)

- This induces an EMF in the coil, which causes a current to flow (1)

MS3:

- EMF = BNL (v⁄t) (1)

- EMF = (0.2 T) × (200 turns) × (0.05 m²) × (90° ÷ 180°) × (1⁄0.1 s) (1)

- EMF = 1.7 V (1)

MS4:

- The EMF induced in a conductor is directly proportional to the rate of change of magnetic flux through the conductor (1)

- Mathematically expressed as: EMF = -dΦ⁄dt (1)

MS5:

- A transformer consists of two coils linked by a magnetic core (1)

- The AC current flowing through the primary coil creates an alternating magnetic field (1)

- The alternating magnetic field induces an EMF in the secondary coil, which is proportional to the number of turns in each coil (1)

MS6:

- Vp⁄Vp = Ns⁄Np (1)

- Vp = 240 V (1)

- Vp = (500 turns)⁄(1000 turns) × 240 V (1)

- Vp = 120 V (1)

MS7:

- Weber (Wb) (2)

MS8:

- A galvanometer is a sensitive instrument that measures small electric currents (1)

- When placed in a changing magnetic field, the current induced in the galvanometer causes the needle to deflect (1)

MS9:

- Slope = 20 V/Wb (2)

- EMF induced is directly proportional to the rate of change of magnetic flux (2)

MS10:

- MRI (Magnetic Resonance Imaging) uses a strong magnetic field and radiofrequency pulses to generate images of the body (1)

- The radiofrequency pulses cause hydrogen atoms in the body to align with the magnetic field (1)

- When the radiofrequency pulses are turned off, the hydrogen atoms release energy in the form of radio waves (1)

- The radio waves are detected by a receiver and used to create images of the body (1)