CBSE Class 10 Science Boards 2021 Sample Paper Solved

5 Both a spherical mirror and a thin spherical lens have a focal length of (-)15 cm. What type of mirror and lens are these?

 

6 The image formed by a concave mirror is observed to be real, inverted and larger than the object. Where is the object placed?

OR

Name the part of a lens through which a ray of light passes without suffering any deviation.

 

7 In the arrangement shown in figure there are two coils wound on a nonconducting cylindrical rod. Initially the key is not inserted in the circuit. Later the key is inserted and then removed shortly after.

8 Draw the magnetic field lines around a straight current carrying conductor. 

 

9 Two unequal resistances are connected in parallel. If you are not provided with any other parameters (eg. numerical values of I and R), what can be said about the voltage drop across the two resistors?

OR

Some work is done to move a charge Q from infinity to a point A in space. The potential of the point A is given as V. What is the work done to move this charge from infinity in terms of Q and V?

 

10 Veins are thin walled and have valves. Justify.

 

11 How is the wall of small intestine adapted for performing the function of absorption of food?

OR

Out of a goat and a tiger, which one will have a longer small intestine? Justify your answer.

 

12 Explain how ozone being a deadly poison can still perform an essential function for our environment.

OR

Give reason why a food chain cannot have more than four trophic levels.