ISC 2017 Physics Practical Question Paper for Class 12

About this paper

This is ISC Class 12 Physics Paper 2 (Practical), set by CISCE for the 2017 examination (paper code 861 B). It carries 30 marks and runs for three hours plus fifteen minutes of reading time, with no more than one and a half hours to be spent on each experiment. Question 1 finds the focal length of a convex lens by the no parallax method for object distances from 70 cm down to 30 cm, with a graph whose slope gives F. Question 2 uses a potentiometer: Part A finds the potential gradient K of the wire from voltmeter readings at five lengths, and Part B uses it to find the emf of a dry cell from the balancing length. Question 3 is the assessment of the project and practical file by the Visiting Examiner.

Exam

ISC Class 12

Subject

Physics Practical

Year

2017

Paper code

861 B

Maximum marks

30

Time allowed

3 hours + 15 min reading

Questions

3

Pages

4

Answers included

No, questions only

Paper pattern

• Question 1

  9 marks

  Focal length of a convex lens by the no parallax method, with a graph of y against x

• Question 2

  6 marks

  Potentiometer: potential gradient of the wire (Part A) and emf of a dry cell (Part B), 4 + 2 marks

• Question 3

  15 marks

  Project (10 marks) and Physics practical file (5 marks) shown to the Visiting Examiner

Topics covered

• Focal length of a convex lens
• No parallax method
• Potentiometer and potential gradient
• Emf of a cell
• Least count of ammeter and voltmeter
• Graph plotting and slope of the line of best fit
• Project and practical file

Questions from this paper

1. Determine the approximate focal length of the given convex lens by projecting the image of a distant object on a wall or screen, and record it in cm correct to one decimal place.
2. With the object pin at the 0 cm mark and the lens at the 70.0 cm mark, remove the tip-to-tip parallax between the image pin and the inverted image and measure the image distance v; repeat for u = 60.0 cm, 50.0 cm, 40.0 cm and 30.0 cm.
3. Determine and record the least count of the given ammeter and voltmeter.
4. With E kept at about 3.5 V to 4 V, record the voltmeter reading for AC = 20.0 cm, 40.0 cm, 60.0 cm, 80.0 cm and 100.0 cm, calculate the potential gradient K for each and find its mean K₀.
5. Replace the voltmeter with a dry cell and a central zero galvanometer, find the balancing length l, and calculate the emf of the dry cell using ε = K₀l, correct to two decimal places.