# Key Guidelines for CBSE Class 12 Physics Practical

Central Board of Secondary Examination has released date sheet for the Class 12th Board Examinations. As few days left for the examinations, students are engrossed in preparing for the examination. As a result, most of the students skip preparing for their practical examination which is also as important part for grabbing good score. Practical contains 30 Marks.

**Syllabus for Physics Practical**

- Two experiments: 8+8 Marks (One from each section)
- Practical Record (Experiments & Activities): 6 Marks
- Project: 3 Marks
- Viva on Experiments and Project: 5 Marks

**SECTION A: Experiments**

- To find resistance of a given wire using metre bridge and hence determine the specific resistance of its material
- To determine resistance per cm of a given wire by plotting a graph of potential difference versus current.
- To verify the laws of combination (series/parallel) of resistances using a metre bridge.
- To compare the EMF of two given primary cells using potentiometer.
- To determine the internal resistance of given primary cell using potentiometer.
- To determine resistance of a galvanometer by half-deflection method and to find its figure of merit.
- To convert the given galvanometer (of known resistance and figure of merit) into an ammeter and voltmeter of desired range and to verify the same.
- To find the frequency of the a.c. mains with a sonometer.

**SECTION B: Experiments**

- To find the value of v for different values of u in case of a concave mirror and to find the focal length.
- To find the focal length of a convex mirror, using a convex lens.
- To find the focal length of a convex lens by plotting graphs between u and v or between 1/u and 1/v.
- To find the focal length of a concave lens, using a convex lens.
- To determine angle of minimum deviation for a given prism by plotting a graph between angle of incidence and angle of deviation.
- To determine refractive index of a glass slab using a travelling microscope.
- To find refractive index of a liquid by using (i) concave mirror, (ii) convex lens and plane mirror.
- To draw the I-V characteristic curve of a p-n junction in forward bias and reverse bias.
- To draw the characteristic curve of a zener diode and to determine its reverse break down voltage.
- To study the characteristic of a common - emitter npn or pnp transistor and to find out the values of current and voltage gains.

**Guidelines **

- Thoroughly read the complete theory behind the experiment
- Understand Graph: Graphs, important part of Physics practical exams, students need to practice them
- Revise Practical notes
- Imagine the diagram of the experiment and draw it roughly
- Experiments are develop to prove the Physics principle. Hence, remember the main principle behind performing the particular experiment.
- Methodology and Principle are the frequently asked questions during viva.
- Don’t be nervous at the time of experiment and write the important steps before starting the practical
- In case of any doubt, consult with the teacher or lab attendant.