# Solved papers for 10th Class Science Solved Paper - Science-2015 Outside Delhi Set-III

### done Solved Paper - Science-2015 Outside Delhi Set-III

• question_answer1) Write the number of covalent bonds in the molecule of butane, ${{\mathbf{C}}_{\mathbf{4}}}{{\mathbf{H}}_{\mathbf{10}}}$.

• question_answer2) Name two simple organisms having the ability of regeneration.

 Which of the following are always at second trophic level of food chains? Carnivores, Autotrophs, Herbivores.

• question_answer4) Draw a ray diagram to show the path of the reflected ray corresponding to an incident ray of light parallel to the principal axis of a convex mirror and show the angle of incidence and angle of reflection on it.

• question_answer5) Why is sustainable management of natural resources necessary? Out of the two-reuse and recycle - which, in your opinion, is better to practise? Give reason.

• question_answer6) Write the name and general formula of a chain of hydrocarbons in which an addition reaction with hydrogen is possible. State the essential condition for an addition reaction stating this condition, write a chemical equation giving the name of the reactants and the product of the reaction.

 Given below are some elements of the modern periodic table. Atomic number of the element is given in the parentheses: A(4), B(9), C(14), D(19), E(20) (a) Select the element that has one electron in the outermost shell. Also write the electronic configuration of this element. (b) Which two elements amongst belong to the same group? Give reason for your answer. (c) Which two elements amongst these belong to the same period? Which one of the two has bigger atomic radius?

 Identify A, B and C in. the given diagram and write one function of each.

• question_answer9) List four categories of contraceptive methods. State in brief two advantages of adopting such preventive methods.

• question_answer10) An object of height 5 cm is placed perpendicular to the principal axis of a concave lens of focal length 10 cm. If the distance of the object from the optical centre of the lens is 20 cm, determine the position, nature and size of the image formed using the lens formula.