Science Delhi (Set 2)

General Instructions:

Read the following instructions very carefully and strictly follow them:

1. Question paper comprises three sections - A, B and C.

There are 30 questions in the question paper. All questions are compulsory.

1. Section A - question no. 1 to 14 - all questions or part thereof are of one mark

each. These questions comprises multiple choice questions (MCQ), very short answer (VSA), and Assertion-Reason type questions. Answer to these questions should be given in one word or one sentence.

1. Section B - question no. 15 to 24 are short answer type questions, carrying 3 marks each. Answer to these questions should not exceed 50 to 60 words.
2. Section C - question no. 25 to 30 are long answer type questions, carrying 5 marks each. Answer to these questions should not exceed 80 to 90 words.
3. Answer should be brief and to the point. Also the above mentioned word limit be adhered to as far as possible.
4. There is no overall choice in the question paper. However, an internal choice has been provided in some questions in each Section. Only one of the choices in such questions have to be attempted.
5. In addition to this, separate instructions are given with each section and question, wherever necessary.

Science Delhi (Set 2)

Question 1

Name the functional group present in propanone.

Solution:

The functional group present in propanone is a ketone.

Question 2

The change in magnetic field lines in a coil is the cause of induced electric current in it. Name the underlying phenomenon.

Solution:

The phenomenon is Electromagnetic Induction

Question 3

The growing size of the human population is a cause of concern for all people. The rate of birth and death in a given population will determine its size. Reproduction is the process by which organisms increase their population. The process of sexual maturation for reproduction is gradual and takes place while general body growth is still going on. Some degree of sexual maturation does not necessarily mean that the mind or body is ready for sexual acts or for having and bringing up children. Various contraceptive devices are being used by human beings to control the size of population.

1. List two common signs of sexual maturation in boys and girls.
2. What is the result of reckless female foeticide?
3. Which contraceptive method changes the hormonal balance of the body?
4. Write two factors that determine the size of a population.

Solution:

1. Two common signs for sexual maturation in boys and girls are as follows:
2. Broadening of shoulder and chest in boys and development of mammary gland or breast in girls.
3. Appearance of hairs on various body parts like pubic area, armpits and face.
4. The number of females will become very low in comparison to the males. Hence, there will be a huge imbalance between male female ratio in the population.
5. Chemical method of contraception e.g. Oral pills interferes with the hormonal balance of the body.
6. Birth rate and death rate are factors that determine the size of a population.

Question 4