Science and Technology Paper One

Time : 3 hours    

Max Marks: 80       

SECTION 'A'

1. (A) Answer the following sub - questions. (5 Marks)

1. The device used for producing current is called a ..................... .

(a) voltmeter (b) ammeter (c) galvanometer (d) generator

2. At the time of short circuit, the current in the circuit ..................... .

(a) increases (b) decreases (c) remains (d) increases in steps

3. The direction of the magnetic field around a straight conductor carrying current is given by

.....................

(a) right hand rule (b) Fleming’s left hand rule (c) Fleming’s right hand rule (d) none of these

4. The relation between electricity and magnetism was first established by ..................... .

(a) Ohm (b) Ampere (c) Oersted (d) Moseley

5. The region around magnet is called as .............. .

(a) magnetic Area (b) magnetic field (c) magnetic loop (d) magnetism

(B) Rewrite the following statements by selecting the correct  options: (5 Marks)

1. The image formed by a concave mirror is ..................... .

(a) always virtual and erect

(b) always virtual and inverted

(c) virtual if the object is placed between pole and focus 

(d) virtual if the object is beyond  focus

2. A concave mirror forms a virtual image of an object placed ..................... .

(a) at infinity

(b) at the centre of curvature of the mirror

(c) at the focus of the mirror

(d) between the focus and the mirror

3. A convex mirror always forms an image which is ..................... than the object size.

 (a) larger

(b) smaller

(c) double

(d) three times

4. No matter how far you stand from a spherical mirror, your image appears erect. The mirror may be ...........

 (a) Plane

(b) concave

(c) convex

(d) either plane or convex

 5. In case of a concave mirror, an erect image is ..................... .

 (a) real and enlarged

(b) real and diminished

(c) virtual and diminished

(d) virtual and enlarged

2. Attempt the following. (10 Marks)

1. Atomic size increases down the group

2. What is the importance of chemical equation?

3. How do metal carbonates reacts with acids?

4. Explain why a conductor is heated when current flows through it.

 5. State general precautions for safety with respect to electricity.

3. Attempt the following. (15 Marks)

1. State the different positions of sources of light with respect to the concave mirror.

2.   What do you mean by dispersion? Name the different colours of light inthe proper sequence in the spectrum of light.

3. Write Short notes on :Earthing.

4. Two dissimilar bulbs are connected in series, bulb will be brighter? (Hint: consider the resistance of the bulb).

5. Define the following: 

Acids.

Bases.

Saponification.

Q4. Attempt the following (any 1) ( 5 marks)

1. We feel fresh while on a morning walk in natural surroundings. Why don't we feel the same after 10 a.m. and during rush hours? Write a chemical reaction to support your statement?

2. Explain the zig-zag line in the periodic table.

Section B

5. (A) Fill in the blanks (5 Marks)

*1. In ..................... mode of reproduction, the offsprings are with minor differences. (Asexual)

*2. Both the parents contribute equal amount of ..................... material to the offspring. (Genetic)

*3. Dominant character masks the ..................... character. (Recessive)

*4. Selection by nature is not ..................... but ..................... . (Deliberate, natural)

5. Mendel’s experiments were based on a number of visible contrasting characters of garden peas _________ (Pisum sativum)

(B) Fill in the blanks (5 Marks)

1. A fragment of DNA that provides complete information about one protein is known as the ..................... for that protein. (Gene)

2. All children inherit ..................... chromosome from their mother. (X)

3. 3. Sex determination in human beings is ..................... . (Genetical)

4. ..................... are collected from different levels of depths. (Fossils)

5. Minor differences occur in asexual reproduction due to inaccuracies occuring in ..................... . (DNA copying)

6. Attempt the following. (10 Marks)

1. Give Scientific Reason : Sodium is stored under kerosene.

2. WRITE SHORT NOTES ON : Catenation

 3. Draw neat and labelled diagram: Human excretory sytem [Diagram]

4. Explain the following Term: Hydrotropic movement

 5. Describe sexual reproduction in plants.

7. Attempt the following. (15 Marks)

 1. Distinguish Between: Degradable Pollutants V/s Non Degradable Pollutants.

2. Give Scientific Reason: Electrolysis of active metals like Na, K, Al is not carried out by using aqueous solution of their chloride.

3. Mention one provision on environment given in our constitution.

4 . How do plants get rid of their excretory products?

5. Write Short notes on: Reflex action

8. Attempt the following (5 marks.)

1. Explain the structure and function of a nephron.

2. Write the functions of the following organs in reproduction. Vagina, Stigma, Ovaries, Seminal vesicle and Prostate glands, uterus.