Question Discussion & Solution

Explanation:

Hygrometer:

• A hygrometer is an instrument used to measure the amount of water vapour in the air (humidity), in soil, or in confined spaces.
• Humidity measurement instruments usually rely on measurements of some other quantities such as -
  • Temperature, pressure, mass, a mechanical or electrical change in a substance as moisture is absorbed.

Additional Information

Hydrometer:

• A hydrometer is an instrument used for measuring the relative density of liquids based on the concept of buoyancy.
• They are typically calibrated and graduated with one or more scales such as specific gravity.
• Hydrometers can be divided into two general classes -
  • liquids heavier than water 
  • liquids lighter than water

A photometer is used to measure the intensity of light produced by an unknown source in terms of a standard source.

• It is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum.
• Most photometers convert light into an electric current using a photoresistor, photodiode, or photomultiplier.
• Photometers are used to determine the correct exposure in photography.
• Photometers measure Illuminance, Irradiance, Light absorption, Scattering of light, Reflection of light, Fluorescence, Phosphorescence and Luminescence.

The correct answer is Outline.

Key Points

• Outline View
  • ​The Outline view shows the different levels of headings as designated by the styles applied in your document.
  • Headings are like titles in your document that explain the section of text to follow.
  • Each heading in the Outline view is indicated by symbols.
• Bold, Italic and Underline font style in MS Word
  • These commands are given in the Font group in the Home tab. 
    • Bold:
      • It allows you to Bold the text of your document
    • Italic:
      • It allows you to Italicize the text of your document
    • Underline:
      • It allows you to underline the text of your document.

Additional Information

• The basic steps to change the font of a text in a document are given below;
  • Select the text you want to modify
  • Select the Home tab and locate the Font group
  • Click the drop-down arrow next to the font style box
  • Font style menu appears
  • With a left-click select the desired font style
  • If you want to change the font to bold or italic, click the 'B' or 'I' icons on the format bar.
  • 

The correct answer is Drag and Drop.

• The action of using the mouse to move an item on the computer screen to a new location is called Drag and Drop.
• Drag and drop is a common action performed within a graphical user interface that involves moving the cursor over an object, selecting it, and moving it to a new location.
• While using a mouse, we can drag and drop an object by clicking the mouse button to select an object, then moving the mouse while keeping the mouse button pushed down. This is called "dragging" the object.
• After moving the object where we want to place it, we can lift up the mouse button to "drop" the object in the new location. 
• Copy and paste are commands in a computer user interface and are one method of transferring data from one location to another. It creates a duplicate in the new location and enables simple data replication.
• Cut removes the item from its current location and places it into the clipboard. Paste inserts the current clipboard contents into the new location.
• Plug and Play is a phrase used to describe devices that work with a computer system as soon as they are connected.

The correct answer is Concave lens.

Key Points

• To treat the eye disease known as myopia or nearsightedness we use the Concave Lens.
• A concave lens is a category of lens that deviates a straight light beam coming from the origin to a diminished, upright, virtual image.
• It can construct both real and virtual images.
• The convex lens is a lens that tends to meet at a point of rays of light that convey parallel to its principal axis which is comparatively thick across the middle and thin at the lower and upper edges.
• A convex lens is used in cameras, correction of Hyperopia, etc.
• Bifocal lenses hold two different prescriptions, an upper part to allow for distance vision and an additional power on the bottom part of the lens to help in close-up focus.
• A bifocal lens is used in people suffering from presbyopia, myopia, hyperopia, and astigmatism.
• The result is eyesight lucidity at both distance and near with one pair of glasses.
• A Compound lens is simple lenses made on a general axis usually in close proximity and often cemented with each other.

Additional Information

If a mirror is placed on the line AB, then we will get this mirror image  -