Questions

Manoeuvre is correctly spelt which means series of moves requiring skill and care.

Page swapping or page replacements are called page cannibalizing.

Let their edges be a and b. Then,

a3/b3 = 1/27 (or) (a/b)3 = (1/3)3 (or) (a/b) = (1/3).

\Ratio of their surface area = 6a2/6b2 = a2/b2 = (a/b)2 = 1/9, i.e. 1:9.

The question tag ‘isn’t it’ needs to be replaced with ‘can’t we’. This is because the sentence and the question tag must be in the same tense and the same pronoun is to be used in the question tag. Thus, the correct formation would be, ‘we can go out whenever we choose to, can’t we?’

The slot covers on a computer reduce the dust build up inside the computer. So the slot covers should be present in proper place.The missing covers can disrupt the airflow design of the case and cause overheating problems.

A periscope is an optical instrument that uses a system of prisms, lenses, or mirrors to reflect images through a tube.

Light from a distant object strikes the top mirror and is then reflected at an angle of 90 degrees down the periscope tube. At the bottom of the periscope, the light strikes another mirror and is then reflected into the viewer’s eye.

Hence, A periscope works by the principle of Total internal reflection.