State the rule to determine the direction of a (i) magnetic field produced around a straight conductor-carrying current, (ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it, and (iii) current induced in a coil due to its rotation in a magnetic field.
Right-hand thumb rule: Imagine that you are holding a current-carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your fingers will wrap around the conductor in the direction of the field lines of the magnetic field. This is known as the right-hand thumb rule and is used to determine the direction of the magnetic field produced around a straight conductor carrying current.
Fleming's left-hand rule: According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or the force acting on the conductor. This rule is used to determine the direction of force experienced by a current-carrying conductor placed in a magnetic field perpendicular to it.
The provided context does not explicitly state the rule for determining the direction of current induced in a coil due to its rotation in a magnetic field. The context mentions that electric generators are devices that use current-carrying conductors and magnetic fields, but the specific rule for induced current direction is not provided.
Explanation
The question asks for three rules related to electromagnetic phenomena. Parts (i) and (ii) are clearly answered from the provided context using the right-hand thumb rule and Fleming's left-hand rule respectively. For part (iii), the textbook would typically include Fleming's right-hand rule, where the forefinger points in the direction of the magnetic field, the thumb points in the direction of motion of the conductor, and the middle finger points in the direction of the induced current. However, this rule is not explicitly stated in the provided context.