# ISC Class 12 Physics Sample Question Papers With Solutions Download PDF

ICSE Class 12 Physics exam paper contains the questions from the different parts of the syllabus. The students who all belong to ICSE 12th Board need to prepare the Physics paper with the best study material. ICSE 12th Physics Exam will contain the questions as are given below. Download ICSE 12th Board Physics Papers and achieve nice score in exam with full preparations. Better is the practice for numerical portion good is the score obtained in the exam.

Q1: a) Explain the phenomenon of total internal reflection with neat ray diagrams.

1. b) Derive the condition for two thin lenses placed coaxially in contact so as to form an achromatic combination. Why are lenses of opposite nature used to form an achromatic lens combination?
2. c) An astronomical telescope is adjusted to form the final image at infinity. The separation between the lenses is 80 cm. The angular magnification is 15. Calculate the focal lengths of the objective lens and eyepiece.

Q2: a) In a cathode ray-tube, an electron passes through a field, where electric field E and the magnetic field B are uniform and mutually perpendicular. Derive an expression for velocity at which the electron reaches the screen undeflected.

1. b) Calculate the energy and momentum of a photon of wavelength 10000 Ao
2. c) State the laws of photoelectric emission.

Q3: a) In Young’s double slit experiment, using light of wavelength 60 nm, 10th bright fringe is obtained on a screen, 3mm from the centre of the pattern. If the screen is 120 cm away from the slits, calculate:

1. Distance between the two slits
2. Fringe width, i.e. fringe separation

(b) Show graphically how intensity of light varies in Fraunhofer diffraction.

Q4: (a) 1. Mention an experiment for the measurement of charge – to – mass ratio of electron.

1. Using Bohr‟s energy quantization formula for hydrogen atom find wavelengths of first two lines of the Balmer series.

(b) 1. Explain the statement: “Work function of a certain metal is 2.0 eV.”

1. Calculate the maximum wavelength of electro-magnetic radiation which will cause photo emission from this metal.

(c) What is de Broglie hypothesis? Write down an experiment that proved de Broglie hypothesis.