Q. One eye is sufficient to form the image of an object. What is the advantage of having two eyes ?

A. The area seen clearly with one eye is comparatively little (approximate range 135°) than with two eyes (range 180°). Two eyes also give better judgement of distances of different objects.
The left eye sees more of the right side of the object and the right eye, more of the left side. Thus, two eyes do not form exactly similar images and the fusion of these two dissimilar images in the brain gives the three dimensional or the stereoscopic vision.

Q. Why do we bring our hands close to the mouth while shouting to somebody at a distance ?

A. By bringing the hands close to our mouth, the sound energy is not allowed to spread in all directions, rather being made unidirectional {i.e., directed in a particular direction). Hence, the sound produced is louder.

Q. Why are fuses provided for electric installations ?

A. A safety fuse is a wire made up of a material having a low melting point. It is inserted in an electrical circuit as a safety device not to allow excess current to flow through the circuit. When the current exceeds the limiting value, the fuse wire gets heated, melts and breaks the circuit.

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Prafull is founder of Syskool. He is an independent blog writer, writes mostly on contemporary topics related to education. Connect