The magnetic force on a moving charged particle is F → = q v → × B → . Which two pairs of the vectors F → , v → , B → are always perpendicular to each other ?

From the property of the cross product, the pairs F → , v → and F → , B → are always at the right angle to each other. Because F → is always perpendicular to the plane containing B → and v → . Vectors B → and v → may have any angle between them.

Ampere or ‘amp’ is a unit of electric current denoted by A . One ampere of current represents one coulomb of electrical charge, i.e. 6 . 24 × 10 18 charge carriers, moving in one second. In other words, an ampere is the amount of current produced by the force of one volt acting through a resistance of one ohm. It is one among the basic seven SI units.

How is a galvanometer converted to an ammeter?

As we know that, a galvanometer is a device that is used to detect small electric current flowing in the circuit and an ammeter is an instrument used to measure the current in a circuit. And ammeter is connected in series with the circuit. It is a low resistance instrument. A Galvanometer is converted into an ammeter by connecting a low resistance S of suitable value in parallel with the galvanometer coil. Here, S = G I g I - I g where, G = Resistance of the Galvanometer