Important questions for 12th standard physics half yearly in Chennai district 2025-26

Here are some important questions -

1) Derive the expression for the electric field due to an electric dipole on its axial line. Also find the potential due to a dipole at a distant point.

2) A parallel plate capacitor has plate separation "d" and area "a". Insert a dielectric slab of thickness d/2. Find the new capacitance, stored energy, and field inside dielectric and air portion.

4) Derive Ohm's law via drift velocity concept.

5) Analyze a circuit with three resistors, two in series, one in parallel - find equivalent resistance, current distribution, and power dissipation.

6) A circular loop is rotated with uniform angular speed in a uniform magnetic field. Derive the expression for induced emf as a function of time.

7) Using mirror and lens formulae, locate the image for a given object distance for (a) concave mirror (b) convex lens. Also, find magnification.

8) If a nucleus undergoes alpha decay, derive the expression for kinetic energy released. Explain the concept of binding energy per nucleon and its variation with mass number.

9) Explain working principle of a PN junction diode and a Zener diode. Draw their I-V characteristics and state their applications.

10) For Young’s double-slit experiment: derive the expression for fringe width and calculate fringe width given wavelength, slit separation and screen distance.