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CBSE Class 12 Physics Practicals: Experiments and Viva

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Physics

CBSE Class 12 Physics practicals and viva questions

Every experiment and activity in the CBSE Class 12 Physics practical syllabus for 2026-27, in the board's order. Each written experiment has the aim, apparatus, principle, procedure, the observation table to draw, the calculation, the result, precautions, sources of error, likely viva questions with short answers, and the slips that cost marks.

How it is marked: Practical exam, 30 marks, 3 hours: two experiments, one from each section (7 + 7), practical record of experiments and activities (5), one activity from any section (3), investigatory project (3), viva on experiments, activities and project (5). The record must hold at least 8 experiments (4 from each section) and 6 activities (3 from each section).

8 of 28 experiments and activities written so far; the rest are coming.

Section A

Experiments

  1. 1. Resistivity of a wire from the V-I graphTo determine resistivity of two / three wires by plotting a graph for potential difference versus current.Read
  2. 2. Metre bridge: resistance of a wireTo find resistance of a given wire / standard resistor using metre bridge.Read
  3. 3. To verify the laws of combination (series) of resistances using a metre bridge. OR To verify the laws of combination (parallel) of resistances using a metre bridge.Coming
  4. 4. Galvanometer: half-deflection method and figure of meritTo determine resistance of a galvanometer by half-deflection method and to find its figure of merit.Read
  5. 5. To convert the given galvanometer (of known resistance and figure of merit) into a voltmeter of desired range and to verify the same. OR To convert the given galvanometer (of known resistance and figure of merit) into an ammeter of desired range and to verify the same.Coming
  6. 6. To find the frequency of AC mains with a sonometer.Coming

Activities

  1. 1. To measure the resistance and impedance of an inductor with or without iron core.Coming
  2. 2. To measure resistance, voltage (AC/DC), current (AC) and check continuity of a given circuit using multimeter.Coming
  3. 3. To assemble a household circuit comprising three bulbs, three (on/off) switches, a fuse and a power source.Coming
  4. 4. To assemble the components of a given electrical circuit.Coming
  5. 5. To study the variation in potential drop with length of a wire for a steady current.Coming
  6. 6. To draw the diagram of a given open circuit comprising at least a battery, resistor/rheostat, key, ammeter and voltmeter. Mark the components that are not connected in proper order and correct the circuit and also the circuit diagram.Coming

Section B

Experiments

  1. 1. Concave mirror: u-v method for focal lengthTo find the value of v for different values of u in case of a concave mirror and to find the focal length.Read
  2. 2. To find the focal length of a convex mirror, using a convex lens.Coming
  3. 3. Convex lens: focal length from u-v and 1/u-1/v graphsTo find the focal length of a convex lens by plotting graphs between u and v or between 1/u and 1/v.Read
  4. 4. To find the focal length of a concave lens, using a convex lens.Coming
  5. 5. Prism: angle of minimum deviation from the i-δ graphTo determine angle of minimum deviation for a given prism by plotting a graph between angle of incidence and angle of deviation.Read
  6. 6. To determine refractive index of a glass slab using a travelling microscope.Coming
  7. 7. Refractive index of a liquid: convex lens and plane mirrorTo find the refractive index of a liquid using convex lens and plane mirror.Read
  8. 8. To find the refractive index of a liquid using a concave mirror and a plane mirror.Coming
  9. 9. p-n junction diode: I-V characteristicsTo draw the I-V characteristic curve for a p-n junction diode in forward and reverse bias.Read

Activities

  1. 1. To identify a diode, an LED, a resistor and a capacitor from a mixed collection of such items.Coming
  2. 2. Use of multimeter to see the unidirectional flow of current in case of a diode and an LED and check whether a given electronic component (e.g., diode) is in working order.Coming
  3. 3. To study effect of intensity of light (by varying distance of the source) on an LDR.Coming
  4. 4. To observe refraction and lateral deviation of a beam of light incident obliquely on a glass slab.Coming
  5. 5. To observe diffraction of light due to a thin slit.Coming
  6. 6. To study the nature and size of the image formed by a (i) convex lens, or (ii) concave mirror, on a screen by using a candle and a screen (for different distances of the candle from the lens/mirror).Coming
  7. 7. To obtain a lens combination with the specified focal length by using two lenses from the given set of lenses.Coming

List copied from: CBSE Physics (042) curriculum 2026-27, Class XII practicals