Physics, Class XII 2024-25, Sample Paper 01
Class
XII 2024-25
Physics
Sample
Paper 01
Time:3 Hours Max.Marks:70
General Instructions:
1. There are 33 questions in all. All questions are compulsory.
2. This question paper has five sections: Section A, Section B, Section C, Section D and Section E.
3. All the sections are compulsory.
4. Section A contains sixteen questions, twelve MCQ and four assertion reasoning based of 1 mark each, Section B contains five questions of 2 marks each, Section C contains seven questions of 3 marks each, Section D contains two case study-based questions of 4 marks each and Section E contains three long questions of 5 marks each.
5. There is no overall choice. However, an internal choice has been provided in one question in Section B, one question in Section C, one question in each CBQ in Section D, and all three questions in Section E. You have to attempt only one of the choices in such questions
6. Use of calculators is not allowed.
7. You may use the following values of physical constants wherever necessary
i. c = 3 × 108 m/s
ii. me = 9.1×10−31 kg
iii. e =1.6 ×10−19 C
iv. µ0 = 4π ×10−7 TmA−1
v. h = 6.63 ×10−34 Js
vi. ε0 = 8.854 ×10−12 C2N−1m−2
vii. Avogadro’s number = 6.023 × 1023 per gram mole
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SECTION-A
1. When a body is connected to the earth, then electrons from the earth flow into the body. It means that the body is
(a) Unchanged
(b) an insulator
(c) Positively charged
(d) negatively charged
2. A bar magnet of magnetic moment M is cut into two parts of equal length. The magnetic moment of either part is
(a) M
(b) M/2
(c) 2M
(d) Zero
3. The radius of curvature of the plane mirror is,
(a) Infinite
(b) zero
(c) + 5 cm
(d) – 5 cm
4. The interference occurs in which of the following waves?
(a) Transverse
(b) longitudinal
(c) Electromagnetic
(d) all of these
5. Rutherford’s α-particle experiment showed that the atoms have
(a) Proton
(b) nucleus
(c) Neutron
(d) electrons
6. The net charge on a current-carrying conductor is
(a) Zero
(b) constant
(c) Varying
(d) negative
7. Lenz’s law is associated with principle of conservation of
(a) Charge
(b) mass
(c) Energy
(d) momentum
8. If the uniform electric field exists along X-axis, then equipotential is along
(a) XY-plane
(b) XZ-plane
(c) YZ-plane
(d) anywhere
9. The value of peak A C in a220 V mains is
(a) 220V
(b) Square Root of 110
V
(c) Square Root of 220
V
(d) Square Root of 440
V
10. The direction of transmission of electromagnetic wave is
(a) Parallel to E
(b) Parallel to B
(c) Parallel to B # E
(d) Parallel to E # B
11. If the momentum of a particle is doubled, then its de-Broglie’s wavelength will
(a) Behalf
(b) be two times
(c) Be four times
(d) remain unchanged
12. The direction of the magnetic field produced by a current-carrying small element of any shape is given by
(a) Lenz's law
(b) Newton’s law
(c) Right-hand thumb rule
(d) Fleming's left-hand rule
13. Assertion: The blue colour of the sky appears due to the scattering of the blue colour.
Reason: Blue colour has shortest wave length in visible spectrum.
(a) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
(c) Assertion is correct but Reason is incorrect.
(d) Assertion is correct but Reason is correct.
14. Assertion (A): A small metal ball is suspended in a uniform electric field with an insulated thread. If high-energy X-ray beam falls on the ball, the ball will bed reflected in the electric field.
Reason(R): X-rays emit photoelectrons and metal becomes negatively charged.
(a) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
(c) Assertion is correct but Reason is incorrect.
(d) Assertion is in correct but Reason is correct.
15. Assertion: Standard optical diffraction gratings cannot be used for discriminating between X-ray wave length.
Reason: The grating spacing is not of the order of X-ray wave lengths.
(a) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
(c) Assertion is correct but Reason is incorrect.
(d) Assertion is correct but Reason is correct.
16. Assertion: X-rays travel with the speed of light.
Reason: X-rays are electromagnetic rays.
(a) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion
(c) Assertion is correct but Reason is incorrect.
(d) Assertion is incorrect but Reason is correct.
SECTION-B
17. How does oscillating charge produce electromagnetic waves?
18. A hollow metal sphere of radius 5cm is charged such that the potential on its surface is 10 V. What is the potential at the centre of the sphere?
19. Two identical cells, each of emf E, having negligible internal resistance, are connected in parallel with each other and access an external resistance R. What is the current through this resistance?
20. Define stopping potential.
OR
Write the expression for the de-Broglie wavelength associated with a charged particle having charge q and mass m, when it is accelerated by a potential.
21. State two characteristic properties distinguishing the behavior of para-magnetic and dia-magnetic materials.
SECTION-C
22. Draw the path of rays for an astronomical telescope in normal adjustment.
23. What is the nature of electrostatic force between two-point electric charges q1 and q2 if
(i) q1+ q2 > 0 ?
(ii) q1+ q2 < 0 ?
24. A circular coil of closely wound N turns and radius r carries a current I. Write the expressions for the following:
(i) The magnetic field at its centre.
(ii) The magnetic moment of this coil.
25. A bar magnet
is moved in the direction indicated by the arrow between two coils PQ and CD. Predict the directions of induced current in each coil.
26. In a typical nuclear reaction, e.g.
Although several nucleons is conserved, energy is released. How? Explain.
27. Conduction and displacement currents are individually discontinuous, but their sum is continuous.
OR
Name the parts of the electromagnetic spectrum that is
(i) Suitable for RADAR systems in aircraft navigation.
(ii) Used to treat muscular strain.
(iii) Used as a diagnostic tool in medicine. Write in brief, how these waves can be produced.
28. What is the difference between diffraction and interference?
SECTION-D
Case
Study Based Questions.
29. A photodiode is an op to an electronic device in which current carriers are generated by photons through photo-excitation i.e., photo conduction by light. It is a p-n junction fabricated from a photosensitive semiconductor and provided with a transparent window so as to allow light to fall on its function. A photodiode can turn its current ON and OFF in nano-seconds. So, it can be used as a fastest photo-detector.
(i) A p- n photodiode is fabricated from a semiconductor with a band gap of 2.5eV. It can detect a signal of wavelength
(a) 4000nm
(b) 6000nm
(c) 4000A0
(d) 6000A0
(ii) Three photo-diodes D1 , D2 and D3 are made of semi-conductor shaving band gap of 2.5eV, 2eV and 3eV, respectively. Which one will be able to detect light of wavelength 6000 A0?
(a) D1
(b)D2
(c) D3
(d) D1 and D2 both
(iii) Photo diode is a device
(a) Which is always operated in reverse bias
(b) Which of always operated in forward bias
(c) In which photo current is independent of intensity of incident radiation
(d) Which may be operated in forward or reverse bias.
(iv) To detect light of wavelength 500nm, the photo diode must be fabricated from a semi-conductor of minimum bandwidth of
(a) 1.24eV
(b) 0.62eV
(c) 2.48eV
(d) 3.2eV
OR
Photo diode can be used as a photo detector to detect
(a) optical signals
(b) electrical signals
(c) both(a)and(b)
(d ) none of these
30. A compound microscope is an optical instrument used for observing highly magnified images of tiny objects. The magnifying power of a compound microscope is defined as the ratio of the angle subtended at the eye by the final image to the angle subtended at the eye by the object, when both the final image and the object are situated at the least distance of distinct vision from the eye. It can be given that: m=me#mo. where me is magnification produced by eye lens and mo, is magnification produced by objective lens. Consider a compound microscope that consists of an objective lens of focal length 2.0 cm and an eye pieceof focal length 6.25 cm separated by a distance of 15 cm.
(i) The object distance for eye-piece, so that final image is formed at the least distance of distinct vision, will be
(a) 3.45cm
(b) 5cm
(c) 1.29cm
(d) 2.59cm
(ii) How far from the objective should an object be placed in order to obtain the conditioned scribed in part(I)?
(a) 4.5cm
(b) 2.5cm
(c)1.5cm
(d) 3.0cm
(iii) What is the magnifying power of the microscope in case of least distinct vision?
(a) 20
(b) 30
(c) 40
(d)10
(iv) The intermediate image formed by the objective of a compound microscope is
(a) real, inverted and magnified
(b) real, erect, and magnified
(c) virtual, erect and magnified
(d) virtual, inverted and magnified
OR
The magnifying power of a compound microscope increases with
(a) the focal length of objective lens is increased and that of eye lens is decreased
(b) The focal length of eye lens is increased and that of objective lens is decreased
(c) Focal lengths of both objects and eye-piece are increased
(d) Focal lengths of both objects and eye-piece are decreased.
SECTION-E
31. What is alternating current? How
alternating e.m.f. and current is represented mathematically. What do you mean
by time period, frequency and amplitude of alternating current?
OR
Show
diagrammatically two different arrangements used for winding the primary and
secondary coils in a transformer. Assuming the transformer to be an ideal one,
write the expression for the ration of its:
(i) Output voltage to input voltage.
(ii) Output current to input current.
Mention
two reasons for energy losses in an actual transformer.
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