Ten questions. The result tells you which lessons you may skip.
A street lamp is \(8\,\text{m}\) high. A man \(2\,\text{m}\) tall stands \(3\,\text{m}\) from its foot. How long is his shadow?
A concave mirror forms a real image three times as far from the pole as the object. By the similar triangles at the pole, the image is
A ray parallel to the axis meets a spherical surface of radius \(20\,\text{cm}\) at a height of \(10\,\text{cm}\). Its angle of incidence is
A lens face of radius \(2\,\text{m}\) rests on a flat plate. How far does it stand above the plate at \(2\,\text{cm}\) from the contact?
The volume of a sphere of radius \(3\,\text{cm}\) is
A drop of radius \(2\,\text{mm}\) has how much surface for each mm³ of water?
A small lamp lights a page. The page is moved to three times the distance. The light on each square centimetre becomes
A point charge \(q\) sits at the centre of a cube. The flux through one face is
A figure draws \(x\) to the right and \(y\) up the page. For right-handed axes, \(z\) points
A positive charge moves along \(+x\) in a magnetic field along \(+y\). The magnetic force on it points along