Semester 2 is of 40 marks. The syllabus consists of 4 units: (i) Sound (ii) Electricity and Magnetism (iii) Heat (iv) Modern Physics.

**(ii) Natural vibrations, Damped vibrations, Forced vibrations** and Resonance - a special case of forced vibrations.

Meaning and simple applications of natural, damped, forced vibrations and resonance.

**(iii) Loudness, pitch and quality of sound**

Definition of each of the characteristics and factors affecting them.

**(i) Ohm's Law**; concepts of emf, potential difference, resistance; resistances in series and parallel, internal resistance.

Concepts of pd (V), current (I), resistance (R) and charge (Q). Ohm's law: statement, V=IR; SI units; graph of V vs I and resistance from slope; ohmic and non-ohmic resistors, factors affecting resistance (including specific resistance) and internal resistance; super conductors, electromotive force (emf); combination of resistances in series and parallel.

Simple numerical problems using the above relations. (Simple network of resistors including not more than four external resistors. Internal resistance may be included).

**(ii) Electrical power and energy.**

Electrical energy; examples of heater, motor, lamp, loudspeaker, etc.

Electrical power; measurement of electrical energy, W = QV = VIt from the definition of pd. Combining with ohm's law W = VIt = I^{2}Rt = (V^{2}/R)t and electrical power P = (W/t) = VI = I^{2}R = V^{2}/R.

Units: SI and commercial; Power rating of common appliances, household consumption of electric energy; calculation of total energy consumed by electrical appliances; W = Pt (kilowatt x hour = kW h), simple numerical problems.

**(iii) Household circuits** - main circuit; switches; fuses; earthing; safety precautions; three-pin plugs; colour coding of wires.

House wiring (ring system) (diagrammatic representation excluded), main circuit (3 wires-live, neutral, earth) with fuse / MCB, main switch and its advantages, need for earthing, fuse, 3-pin plug and socket; Conventional location of live, neutral and earth points in 3 pin plugs and sockets. Safety precautions, colour coding of wires.

**(iv) Magnetic effect of a current** (principles only, laws not required); electromagnetic induction (elementary).

Oersted's experiment on the magnetic effect of electric current; magnetic field (B) and field lines due to current in a straight wire (qualitative only), right hand thumb rule - magnetic field due to a current in a loop;.

Electromagnets: their uses; comparisons with a permanent magnet; conductor carrying current in a magnetic field experiences a force, Fleming’s Left Hand Rule and its understanding, Simple introduction to electromagnetic induction; a magnet moved along the axis of a solenoid induces current, Fleming’s Right Hand Rule and its application in understanding the direction of current in a coil and Lenz’s law, Comparison of AC and DC.

**(i) Calorimetry:** meaning, specific heat capacity; principle of method of mixtures; Numerical Problems on specific heat capacity using heat loss and gain and the method of mixtures.

Heat and its units (calorie, joule), temperature and its units (°C, K); thermal (heat) capacity C' = Q/ΔT (SI unit of C'): Specific heat Capacity C = Q/mΔT (SI unit of C) Mutual relation between Heat Capacity and Specific Heat capacity, values of C for some common substances (ice, water and copper).

Principle of method of mixtures including mathematical statement. Natural phenomenon involving specific heat. Consequences of high specific heat of water. [Simple numerical problems].

**(ii) Latent heat**; loss and gain of heat involving change of state for fusion only.

Change of phase (state); heating curve for water; latent heat; specific latent heat of fusion (SI unit). Simple numerical problems. Common physical phenomena involving latent heat of fusion.

Radioactivity and changes in the nucleus; background radiation and safety precautions.

Brief introduction (qualitative only) of the nucleus, nuclear structure, atomic number (Z), mass number (A). Radioactivity as spontaneous disintegration. α, β and γ - their nature and properties; changes within the nucleus. One example each of α and β decay with equations showing changes in Z and A. Uses of radioactivity - radio isotopes. Harmful effects. Safety precautions. Background radiation.

Radiation: X-rays; radioactive fallout from nuclear plants and other sources.

Nuclear Energy: working on safe disposal of waste. Safety measures to be strictly reinforced.