Maharashtra HSC Physics Answer Key 2025 PDF Out, Check Question Paper PDF, Exam Analysis

SECTION – A

Q1. Select and write the correct answers for the following multiple-choice type of questions: [10]

(i) “If two systems are each in thermal equilibrium with a third system, they are also in thermal equilibrium with each other.” This statement refers to:
(a) zeroth law of thermodynamics
(b) first law of thermodynamics
(c) second law of thermodynamics
(d) Carnot’s law

Answer: (a) zeroth law of thermodynamics

(ii) In Bernoulli’s theorem, which of the following is constant?
(a) Linear momentum
(b) Angular momentum
(c) Mass
(d) Energy

Answer: (d) Energy

(iii) Which of the following materials belongs to a diathermanous substance?
(a) wood
(b) iron
(c) glass
(d) copper
Answer: (c) glass

(iv) Electric potential ‘V’ at a distance ‘r’ from a point charge is directly proportional to _____.
(a) r
(b) r²
(c) 1/r
(d) 1/r²
Answer: (c) 1/r

(v) Which of the following equations gives the correct expression for the internal resistance of a cell by using a potentiometer?
(a) r = R (V/E – 1)
(b) r = R (1 – E/V)
(c) r = R (1 – V/E)
(d) r = R (E/V – 1)
Answer: (c) r = R (1 – V/E)

(vi) An electron, a proton, an α-particle, and a hydrogen atom are moving with the same kinetic energy. The associated de-Broglie wavelength will be longest for –
(a) proton
(b) electron
(c) hydrogen atom
(d) α-particle
Answer: (b) electron

(vii) The gate which produces high output when both inputs are high is –
(a) X-OR gate
(b) AND gate
(c) NAND gate
(d) NOR gate
Answer: (b) AND gate

(viii) The power rating of a ceiling fan rotating with a constant torque of 2 Nm with an angular speed of 2π rad/s will be _____.
(a) π W
(b) 2π W
(c) 3π W
(d) 4π W
Answer: (b) 2π W

(ix) A string of length 2 m is vibrating with 2 loops. The distance between its node and adjacent antinode is _____.
(a) 0.5 m
(b) 1.0 m
(c) 1.5 m
(d) 2.0 m
Answer: (a) 0.5 m

(x) A transformer increases an alternating e.m.f. from 220V to 880V. If the primary coil has 1000 turns, the number of turns in the secondary coil is _____.

(a) 1000
(b) 2000
(c) 3000
(d) 4000
Answer: (b) 2000

Q2. Answer the following questions:

(i) At what temperature does the surface tension of a liquid become zero?
Answer: At the critical temperature of the liquid.

(ii) Define self-inductance.
Answer: Self-inductance is the property of a coil by which it opposes the change in current flowing through it by inducing an electromotive force (emf) in itself.

(iii) What is the work done by an external uniform magnetic field perpendicular to the velocity of a moving charge?
Answer: The work done is zero because the magnetic force is always perpendicular to the velocity, causing circular motion without changing kinetic energy.

(iv) What do you mean by a thermodynamic system?
Answer: A thermodynamic system is a specific region in space or a defined quantity of matter that is under study, where energy and matter exchanges occur with its surroundings.

(v) What is the value of B called when H = 0 in the hysteresis loop?
Answer: It is called remanent magnetization (Br) or remanence.