in a light experiment with a convex lens a student plotted a graph as shown above of the reciprocal of object distance (1)/u against the reciprocal of image distance (1)/v . the focal length of the lens is given as

The water manometer above is measuring the pressure of gas supply. if the specific gravity of mercury is 13.6 and the atmospheric pressure is 70cm of mercury what is the total pressure of the gas supply in cm of water

in the image above, an incident ray XY makes an angle of 15\( ^{\circ} \) with a fixed line AY, which is normal to surface of a plane mirror if the mirror is turned as indicated by the arrow through \( 40^{\circ} \), what angle will the reflected ray make with AY