The principle of which of these devices is based on electromagnetism?

What does the direction of the thumb indicate in the Right-Hand Thumb Rule? In what way is this rule different from Fleming's Left-Hand Rule?

In the diagrams shown below:
$(i)$ Name the type of current in two cases.
$(ii)$ Identify any one source for each type of these currents.
$(iii)$ What is the frequency of current in case $(ii)$ in India?
$(iv)$ Use above graphs to write two differences between the current in two cases.

The most important safety method used for protecting home appliances from short circuiting or overloading is

$A$ student performs an experiment to study the magnetic effect of current around a current-carrying straight conductor with the help of a magnetic compass.
He reports that:
$(i)$ the degree of deflection of the magnetic compass increases when the compass is moved away from the conductor.
$(ii)$ the degree of deflection of the magnetic compass increases when the current through the conductor is increased.
Which of the above observations of the student appears to be wrong and why?

Which instrument is used to know the presence of an electric current in a circuit?