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A man can hear the sound of frequency

   A man can hear the sound of frequency 1 Hz, 1000 Hz, 200 Hz, 5 MHz, Ans.     As you know that a man can hear the sound of frequency between 20 Hz and 20,000 Hz.               Moreover, you know the sounds of frequencies less than 20 Hz i.e. sub sonic and more than 20,000                 Hz i.e. ultrasonic, man can not hear. Therefore correct option is 2. 1000 Hz.
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The image formed by a plane mirror is

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  The image formed by a plane mirror is                                                                        Erect and diminished Erect and enlarged Inverted and of same size Erect and of same size Ans.    As we see in our dressing table mirror or in other domestic mirror, our image is always  erect                   and of same size,  therefore option  4. Erect and of same size  is correct.
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Two plane mirrors are placed making an angle of 60˚ in between them. For an object placed in between the mirrors, the number of images formed will be

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  Two plane mirrors are placed making an angle of  60 ˚ in between them. For an object placed in between the mirrors, the number of images formed will be                                                                                                                                                              3 5 6 Infinite   Ans. As per above figure and as we know that n umber of images formed when two plane mirrors are kept at an angle   q   degrees is:  q 3 6 0 ​ − 1 i.e.,  6 0 3 6 0 ​ − 1 = 6 − 1 = 5 For more description click on Figure after pressing Ctrl...
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A real and enlarged image can be obtained by using

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   A real and enlarged image can be obtained by using  Convex mirror Plane mirror Concave mirror Convex and plane mirror                                                  Ans.     Please see above  to understand clearly that when object AB is between focal point and centre              of curvature, the image A'B' is real and enlarged.            So, it is clear that correct option is  3. Concave mirror
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Convert 1 mm Hg pressure in Pascal. (Density of Hg = 13.6 X 10^6 Kg/m^3 and g = 9.8 m/s^2)

  Convert 1 mm Hg pressure in Pascal. (Density of Hg = 13.6 X 10^6 Kg/m^3 and g = 9.8 m/s^2) 133.28 Pa 133.80 Pa 133.12 Pa 132.98 Pa          Ans. As we know that 760 mm of Hg pressure = 101300 Pa                    1 mm of Hg pressure = 101300/760 = 133.28 Pa,                 Therefore, option  1. 133.28 Pa  is correct.
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A hydrometer is used to measure the following quantity of liquid

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   A hydrometer is used to measure the following quantity of liquid Density Volume Relative density Pressure         Ans.  The correct option is  3. Relative density
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On Fahrenheit scale, the boiling point of water is

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  On Fahrenheit  scale, the boiling point of water is   100 ˚F  98.7 ˚F  212 ˚F  220 ˚F Ans. As per the given figure, boiling point of  water is 212 ˚F , therefore option  3. 212 ˚F  is correct.
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