When two mirrors are placed at an angle of 90º to each other, how many images will be formed when an object is placed in front of the mirrors

Calculate the angle of minimum deviation of a 60º prism of a refractive index 1.5[ \(sin^{-1}\) (0.75) = 49º]

What is the cost of running seven 40 W lamps and five 80 W lamps for 12 hours of the electrical energy cost N7.00kWh?