What is the name of horizontal and vertical lines drawn to determine the position of any point in the cartesian plane?

What is the name of horizontal and the vertical lines drawn to determine the position of any point in the cartesian plane.

A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction vecB as shown in the figure At the position PQR, the speed of the ring is v. Then, the potential difference developed across the ring is

A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction vecB . At the position MNQ, the speed of the ring is v. What is the potential difference developed across the ring at the position MNQ?

Show that the line integral of electric field ntensity between any two points depends only on the position of these points and its independent of the path followed between these points.

Find the differential equation of all non-vertical lines in a plane.

A compass needle free to turn in a horizontal plane is placed at the centre of circular coil of 30 turns and radius 12 cm. The coil is in a vertical plane making an angle of 45^@ with the magnetic meridian. When the current in the coil is 0.35 A, the needle points west to east. Determine the horizontal component of the earth’s magnetic field at the location.

Form the differential equation of all non-horizontal lines in a plane.

Find the coordinates of the vertices of a rectangle, placed in III quadrant in the cartesian plane with length 'a' units on x-axis and breadth 'b' units on y-axis.