Self Studies
Self Studies
Self Studies
Self Studies

Human Eye and Colourful World Test - 54

Result Self Studies

Human Eye and Colourful World Test - 54
  • Score

    -

    out of -
  • Rank

    -

    out of -
TIME Taken - -
Self Studies

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Self Studies Self Studies
Weekly Quiz Competition
  • Question 1
    1 / -0
    After looking the sun the colour of other things appears 
    Solution
    The sun is a giant ball of plasma that can hurt, even destroy, your eyes, so please, do not look directly at the sun! The black you see after looking at the sun is just proof of this. Your eye sees thanks to very delicate receptors on the back of your retina.
  • Question 2
    1 / -0
    A person suffering from short-sightedness can see clearly only upto a distance of 2 metres. Find the power of the lens required to correct his vision
    Solution
    To correct the vision, the object is placed at infinity $$u=-\infty$$ so that its image is formed at his far point, i.e. $$v=-2 \ m$$
    $$\begin{array}{l} { { Re } }quired\, lens\, is\, a\, concave\, lens. \\ v=-2 \ m \\ u=\infty  \\ Now, using \ Lens \ Formula \\ \dfrac { 1 }{ v } -\dfrac { 1 }{ u } =\dfrac { 1 }{ f }  \\ \dfrac { 1 }{ { -2 } } -\dfrac { 1 }{- \infty  } =\dfrac { 1 }{ f }  \\ f=-2m \\ Power \ P=\dfrac { 1 }{ f } =\dfrac { 1 }{- 2 } =-0.5D \end{array}$$
    Hence, the option $$A$$ is the correct answer.
  • Question 3
    1 / -0
    The phenomenon of splitting of sunlight by a prism is called_________  and the color that deviates most is ______
    Solution
    The phenomenon of splitting white light into its seven constituent colours when it passes through a glass prism is called dispersion of white light. The various colors seen are Violet, Indigo, Blue, Green, Yellow, Orange and Red.
    In a spectrum formed by a prism red colour deviates the least and violet colour deviates the most.
  • Question 4
    1 / -0
    Hypermetropia is possible in.........
  • Question 5
    1 / -0
    A student of class $$  10,  $$ is not able to see clearly the black board question when seated at a distance of $$5  \mathrm{m}  $$ from the board,the defect he is suffering from is
    Solution

    From the question we can see that the student is unable to see objects that are away from him clearly. This is the condition for myopia.

    Hence the correct answer is option (A).

  • Question 6
    1 / -0
    A person cannot see the object beyond 200cm. The power of lens used to  correct the vision will be :
    Solution
    Here for the lens needed , it should form image  of an distant object. at distance of $$200 cm$$
    Here, $$u = \infty$$ and $$ v = -200\; cm$$

    $$\Rightarrow \dfrac{1}{f} = \dfrac{1}{v} - \dfrac{1}{u}$$

    $$\Rightarrow \dfrac{1}{f} =- \dfrac{1}{200} + 0$$

    $$\Rightarrow f =-2m$$
    $$\Rightarrow  P (in \; D)= \dfrac{1}{f(in\; m)} =- 0.5 D$$

    Therefore, C is correct option.
  • Question 7
    1 / -0
    The principle section of a glass prism is isosceles triangle ABC with AB=AC, the face AC is silvered. A ray of light is incident normally on the face AB and after two reflections, it emerges from the base BC perpendicular to the base. Angle of BAC of the prism is 
  • Question 8
    1 / -0
    A ray falls on a prism ABC (AB = BC) and travels as shown in figure. The minimum refractive index of the prism material should be 

    Solution
    $$\begin{array}{l} By\, the\, help\, of\, the\, figure \\ { \sin ^{ -1 }  }\left( { \frac { { nr } }{ { nd } }  } \right) =c \\ \Rightarrow \frac { { nr } }{ { nd } } =\sin { 45^{ \circ  } }  \\ \Rightarrow \frac { 1 }{ { nd } } =\frac { 1 }{ { \sqrt { 2 }  } }  \\ \therefore nd=\sqrt { 2 }  \\ Hence,\, the\, option\, B\, \, is\, \, the\, correct\, answer. \end{array}$$
  • Question 9
    1 / -0
    The eyes defect represented by the figure is 

    Solution

  • Question 10
    1 / -0
    Assume nothing else blocks their view, approximately how far can two people stand from each other in clear atmosphere until they can no longer see each other due to the curvature of the Earth? [Take radius of earth $$= 6400 \ km$$]
    (Assume height of each person is $$2 \ m$$.)
    Solution
    Given:
    Height of each person $$h=2 \ m$$
    Radius of earth, $$R=6400 \ km = 6400000 \ m$$
    For a right angled triangle, we see the hypotenuse is $$R+2.$$
    Base and perpendicular are $$R$$ and $$X$$ respectively.
    Using Pythagoras theorem,
    $$(R+2)^2=R^2+X^2$$
    $$X= \sqrt{(R+2)^2-R^2}$$
    The distance we need to find is the length of the tangent $$2X$$.
    So,
    $$\begin{array}{l} 2X=2\sqrt { { { \left( { R+2 } \right)  }^{ 2 } }-{ R^{ 2 } } }  \\ =2\sqrt { 2\left( { 2R+2 } \right)  }  \\ =4\sqrt { R+1 }  \\ =4\sqrt { 6400001\, \, M }  \\ =10119.3\, m\approx 1\, \, km \\ Ans.\, \, (C) \end{array}$$

    If both the people move farther than this distance, their vision will be blocked by the curvature of the earth.

Self Studies
User
Question Analysis

  • Correct -

  • Wrong -

  • Skipped -

My Perfomance
  • Score

    -

    out of -
  • Rank

    -

    out of -
Re-Attempt Weekly Quiz Competition
Self Studies Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Self Studies
Click on Allow to receive notifications
Allow Notification
Self Studies
Self Studies Self Studies
To enable notifications follow this 2 steps:
  • First Click on Secure Icon Self Studies
  • Second click on the toggle icon
Allow Notification
Get latest Exam Updates & FREE Study Material Alerts!
Self Studies ×
Open Now