Check CBSE Class 12 Physics Marking Scheme 2021-22 (Term 1) & Sample Paper (PDF). It is based on Revised CBSE Syllabus and important for preparation of the upcoming CBSE 12th board exam 2021-22 Term 1). Links to download these resources are given at the end of this article.
CBSE Class 12 Physics Marking Scheme 2021-22 (Term 1) & Sample Paper
Subject: Physics (042)
Time: 90 Minutes Max. Marks 35
The Question Paper contains three sections.
Section A has 25 questions. Attempt any 20 questions.
Section B has 24 questions. Attempt any20 questions.
Section C has 6 questions. Attempt any 5 questions.
All questions carry equal marks.
There is no negative marking.
This section consists of 25 multiple choice questions with overall choice to attempt any 20 questions. In case more than desirable number of questions are attempted, ONLY first 20 will be considered for evaluation.
Q1. Which of the following is NOT the property of equipotential surface?
(i) They do not cross each other.
(ii) The rate of change of potential with distance on them is zero.
(iii) For a uniform electric field they are concentric spheres.
(iv) They can be imaginary spheres.
Answer. 1 (iii)
As all other statements are correct. In uniform electric field equipotential surfaces are never
concentric spheres but are planes to Electric field lines.
Q2. Two point charges +8q and -2q are located at x = 0 and x = L respectively. The point on x axis at which net electric field is zero due to these charges is-
(iii) 2 L
Q3. An electric dipole of moment p is placed parallel to the uniform electric field. The amount of work done in rotating the dipole by 900 is-
(ii) W = pE (cosθ1 – cosθ2) 1 = 0
θ1 = 0o
Θ2 = 90o
W = pE (cos 0o - cos 90o ) = pE (1 – 0) = pE
Q4. Three capacitors 2µF, 3µF and 6µF are joined in series with each other.
The equivalent capacitance is-
Answer 4: (ii)
1/Cseries = (1/C1) + (1/C2) + (1/C3)
1/Cseries = (1/2) + (1/3) + (1/6) = (3+2+1)/6 = 1
Q5. Two point charges placed in a medium of dielectric constant 5 are at a distance r between them, experiencing an electrostatic force ‘F’. The electrostatic force between them in vacuum at the same distance r will be-
Q6. Which statement is true for Gauss law-
(i) All the charges whether inside or outside the gaussian surface contribute to the electric flux.
(ii) Electric flux depends upon the geometry of the gaussian surface.
(iii) Gauss theorem can be applied to non-uniform electric field.
(iv) The electric field over the gaussian surface remains continuous and uniform at every point.
Answer 6. (iv)
All other statements except (iv) are in correct
The electric field over the Gaussian surface remains continuous and uniform at every point.
For rest of the questions & answers, download the resources from the links given below