CBSE EXAMINATION PAPER-2024
PHYSICS
(Solved)
General Instructions :
Read the following instructions carefully and follow them :
- This question paper contains 9 questions. All questions are compulsory.
- This question paper is divided into 3 sections.
- Section A – questions number 1 to 3 are multiple choice questions
- Section B – questions number 4 to 6 are very short answer
- Section C – questions number 7 to 9 are short answer
- There is no overall choice given in the question paper. However, an internal choice has been provided in few questions.
- Use of calculator is NOT allowed.
Section A
The quantum nature of light explains the observations on photoelectric effect as-
The correct answer is (A) there is a minimum frequency of incident radiation below which no electrons are emitted. This is because the photoelectric effect demonstrates that only light above a certain frequency can cause the emission of electrons from a metal, which is a key aspect of its quantum nature. If the frequency is too low, no electrons are emitted regardless of the intensity of the light.
A straight wire is kept horizontally along east-west direction. If a steady current flows in wire from east to west, the magnetic field at a point above the wire will point towards.
According to the right-hand rule for current-carrying conductors, if you point your thumb in the direction of the current (east to west), your fingers will curl in the direction of the magnetic field. Therefore, above the wire, the magnetic field will point towards the north.
The magnetic susceptibility for a diamagnetic material is
The correct option is 'small and negative.' Diamagnetic materials have a very small and negative susceptibility, which means they are repelled by magnetic fields. This is due to the absence of unpaired electrons in their atomic structure, resulting in no net magnetic moment.
Section B
Draw the circuit diagram of a p-n junction diode in
(i) forward biasing and (ii) reverse biasing. Also draw its I-V characteristics in the two cases.
Two electric heaters have power ratings P₁ and P₂ at voltage V. They are connected in series to a dc source of voltage V. Find the power consumed by the combination. Will they consume the same power if connected in parallel across the same source?
An air bubble is trapped at point B (CB = 20 cm) in a glass sphere of radius 40 cm and refractive index 1.5 as shown in figure. Find the nature and position of the image of the bubble as seen by an observer at point P.
Section C
Find the current in branch BM in the network shown.
Name the electromagnetic waves with their wavelength range which are
used for
i) FM radio broadcast
ii) detection of fracture in bones
iii) treatment of muscular strain
(b) What are ferromagnetic materials? Explain ferromagnetism with the help of suitable diagrams, using the concept of magnetic domain.
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