F5 Magnetism

Q: Why we cannot use Hall probe in this experiment? If a Hall probe is used , what is the drawback?

A: A Hall probe can only be used to measure the magnetic flux of a static magnetic field. Since ac is used in the experiment, the magnetic field so produced is time varying, hence a Hall probe cannot be used.

Should a Hall probe be inserted into the field of the solenoid, a steady Hall voltage could not be established.

Q: Why the search coil should be perpendicular to the solenoid?

A: This is to ensure that the magnetic field lines passing normally to the plane of the coil. In other words, the search coil can "catch" the maximum field lines and hence the induced emf will be highest.

Q: Does the magnetic field from the Earth affect the experimental reading?Why?

A: No. Earth magnetic field is more or less a static field. Seacrh coil works by electromagentic induction that requires a changing magnetic field. Hence, the static earth magnetic field would not induce any emg on the search coil. There is no effect on the experimental reading.