The Science and Technology paper for Class X (60 marks theory, 20 marks MCQ and 20 marks for Practicals) consists of two sections. Section A (Physics and Chemistry) is for 40 marks, Section B (Biology) is for 20 marks.
Units 2 and 6 of the NCERT textbook include topics covered in Physics. It is possible to score very well in Physics, but understanding the basic concepts is essential. Practise writing the definitions, formulae and units of the physical quantities.

	Pushpa Tyagi

Students commit many common errors and lose marks unnecessarily. Some common errors are -
• Directions in ray /circuit diagram are not marked.
• Sign convention is not correctly used.
• Units are not specified. At times, a different system of units is used in the same formula. It is preferable to use SI system on a uniform basis.
• Diagrams are not labelled.
• Proper bending of light rays is not shown when drawing the ray diagrams for correction of the defects of vision.
Such errors have a poor impact on the overall score.
Hocus focus
Focus on these important areas for the examination:
• Definitions of the terms e.g radius of curvature, focus point, power of a lens, rating of electrical appliances, dispersion, refractive index, potential difference, electrical resistivity, electromagnetic induction, electrolysis and electroplating.
• Diagrams/ ray diagrams: Image formation by mirrors and lenses, dispersion, defects of vision and their correction, magnetic field lines due to a straight carrying current conductor, circular coil and a solenoid.
• Statements of laws - Coulomb's law, Ohm's law, laws of reflection, refraction, Hubbles law, Big Bang theory and steady state theory, laws governing the amount of heat produced due to current passing through the conductor (Joule's laws of heating), laws to determine direction of magnetic field due to a current carrying conductor.
• Derivation of formulae - Relation between radius of curvature and focal length of mirrors and Combination of Resistances.
• Numerical problems on lens and mirror formula, Ohm's law, amount of work done in motion of a charge between two points with a potential difference, combination of resistances, selection of fuse wire, defects of vision, magnification and energy released in nuclear reactions.
• Sources of energy and exploring universe are relatively simple topics but are very important and easy to score. Solar cooker, solar heater, wind, tidal energy, ocean thermal energy conversion and bio gas, Hubble's law, Big Bang and steady state theory and use of stars to find direction etc are some of the important questions.

Fizz up
It is advisable to do a comprehensive study of all topics mainly by written practice. However some of the important questions that need special attention are --
• Discuss the problems of Myopia and Hypermetropia, along with corrective measures in relation to vision of human eye.
• Explain mirage formation, twinkling of stars and conditions for total internal reflection.
• State Ohm's law. How will you find resistance from the voltage - current graph?
• State the factors on which the amount of heat produced by a current carrying conductor depends.
• List the factors affecting resistance.
• Explain the working of solar cooker /heater /bio gas plant.
• Given the three lenses/mirrors, how will you identify them without touching?
• A green shirt is taken to a room where only blue light is present. What would be the appearance of the shirt in this room?
• Which colour will you get on mixing blue and yellow paint?
• Refraction of light through a prism, a rectangular glass slab.
• Names of Indian satellites and launch vehicles
• Difference between renewable and non-renewable sources of energy, fusion and fission, planets and asteroids, meteor and meteorite, remote sensing and geo-stationary satellite.
• What do you understand by greenhouse effect, constellations and artificial satellite? Describe the structure of earth.
• Various abbreviations used in space exploration and laws governing planetary motion.
• Advantages of solid fuel and liquid fuel with examples of each.

Most students start preparations for the exam very late. Some do not practise by writing down the answers and commit common mistakes during the real exam. Even if you have not been serious earlier, if pursued properly, two months are sufficient to score reasonably well in Physics. The focus needs to be on written practise . Learn the formulae, practise derivation, diagrams and the various laws. Dealing with the topics mentioned above will help. Endeavour to remain consistent and be methodical. Now is a good time to start. Full marks can be scored in the subject.