important questions -paper 2

 

IMPORTANT QUESTIONS ------ PHYSICS (SCIENCE)

CLASS    X

 

1.      Distinguish between the terms “overloading and short circuiting” as used in domestic circuits.   (b) Why are the coils of electric toasters made of an alloy rather than a pure metal?

2.      What is meant by dispersion of white light? Describe the formation of rainbow in the sky with the help of a diagram.

3.       What is hypermetropia? Draw ray diagrams to show the image formation of an object by: (i) Hypermetropic eye.  (ii) Correction made with a suitable lens for hypermetropic eye.

4.      Give reason for the following: i)lour of the clear sky is blue.(ii) The sun can be seen about two minutes before actual    sunrise.(iii) We cannot see an object clearly if it is placed very close to the eyes.

5.      What is Presbyopia? Write two causes of this defect.

6.      .Draw a diagram to show the magnetic filed lines around a current carrying solenoid. What do you interpret from the pattern of the field lines?

7.      Difference between real and virtual images.

8.      Write any 4 uses of spherical mirrors.

9.      State the mirror formula.

10.  What is magnification . What is its SI unit.

11.  Draw a ray diagram of image formation when the object is placed in front of a convex lens at different position.

12.  What do you understand by spherical aberration and how it is corrected?

13.  Why do stars twinkle on a clear night?

14.  What is mirage? How does it occur?

15.  What is dispersion? How will you show that sun-light is composes of seven colours?

16.  What is the focal length of a plane mirror?

17.  Draw labelled diagram of human eye and describe its working.

18.  How do we see colours? What is colour blindness?

19.  What do you under stand by “least distance of distinct vision”.

20.  . What is persistence of vision? Write the process where it is used.

21.  Where will the image be formed when the object is placed between the focus and the pole (infinity, pole) of the convex mirror?

22.  With respect to air the refractive index of ice and that of rock salts are 1.31 and 1.54 respectively. Calculate the refractive index of rock salt with respect to ice.

 

 

 

 

23.  With respect to air the refractive index of water and that of benzene are 1.33 and 1.50 respectively. Calculate the refractive index of benzene with respect to water.

24.  A convex mirror used on a truck has 3m radius of curvature. If a bus is located at 5m from this mirror. Find the position, nature and size of the image.

25.  What is accommodation? What is the maximum variation in power of accommodation in human eye?

26.  An object of size 5cm is placed at a distance of 25cm from the pole of a concave mirror of radius of curvature 30cm. Calculate the distance and size of the image formed. What will be the nature of the image?

27.  An object of size 3cm is placed at a distance of 15cm from a convex lens of focal length 10cm. Calculate the distance and size of the image so formed. What will be the nature of image?

28.  Light enters from air to glass plate having refractive index 1.50. What is the speed of light if the speed of light in air is  m/s?

29.  What is dispersion? Which color of light deviates more on passing through a prism? When two prisms are placed together with one inverted and white light is passed, what will be the result? What are the conditions for the formation of rainbow? What are the values for the angle of incidence and angle of reflection for normal incidence?

30.  Which phenomenon does optic fiber work upon?

31.  An object is placed 20cm in front of mirrors M1 and M2 separately and image is found to be formed at a distance of 15cm in front of it in case of M1 and behind it in case of M2. Find the focal length and kind of mirror in each case.