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PHYSICS

This category collects Physics practice questions covering the core areas of the subject, including mechanics, heat and thermodynamics, waves and optics, electricity and magnetism, and modern physics. Use it to test your understanding of concepts and formulas, then review the answers to find the topics that need more work.

45 questions

A neutron ( 1 u ) moving at 2 × 10⁶ m/s collides elastically with a carbon nucleus ( 12 u ). What fraction of its kin

Given: A neutron ( 1 u ) moving at 2 × 10⁶ m/s collides elastically with a carbon nucleus ( 12 u ). What fraction of its kinetic energy is retained? These values define the system as per NCERT data. Formula: Fraction retained f_1 = ( m_1 - m_2/m_1 + m_2 )² = ( 1 - 12/1 + 12 )² = ( -11/13 )² = 121/169 approx 0.716 .. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Substituting values like 1.2 × 10⁻⁵, 236 J kg⁻¹ K⁻¹, CH₃CH₂NH₂ etc. into the formula and simplifying step by step. Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Laws of Motion, Work Energy Power, Gravitation and System of Particles, Topic: Newton's laws, work-energy theorem and rotational dynamics.

A stone is thrown upwards with a speed of 18 m/s . What is its velocity after 2 s ? (Take g = 10 m/s² )

Given: A stone is thrown upwards with a speed of 18 m/s . What is its velocity after 2 s ? (Take g = 10 m/s² ) These values define the system as per NCERT data. Formula: Use v = v_0 + a t. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Here, v_0 = 18 m/s, a = -10 m/s², t = 2 s . Substitute: v = 18 - 10 · 2 = 18 - 20 = -2 m/s . The velocity is -2 m/s (downward). Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Units and Measurements and Physical World, Topic: Dimensional analysis and fundamental principles.

A solenoid of 900 turns/m and area 0.015 m² has μ_r = 2 . What is its self-inductance? ( μ_0 = 4π × 10⁻⁷ H/m )

Given: A solenoid of 900 turns/m and area 0.015 m² has μ_r = 2 . What is its self-inductance? ( μ_0 = 4π × 10⁻⁷ H/m ) These values define the system as per NCERT data. Formula: L = μ_r μ_0 n² A l, assume l = 1 m. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: L = 2 × 4π × 10⁻⁷ × (900)² × 0.015 × 1 = 0.0305 H approx 0.03 H . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Moving Charges and Magnetism and Magnetism and Matter, Topic: Magnetic field due to current loop, solenoid and magnetic dipole moment. Page number should be added only after verification from the.

An electron moves with a speed of 3.0 × 10⁶ m/s . What is its de Broglie wavelength? (Take h = 6.63 × 10⁻³⁴ J s

Given: An electron moves with a speed of 3.0 × 10⁶ m/s . What is its de Broglie wavelength? (Take h = 6.63 × 10⁻³⁴ J s, m_e = 9.11 × 10⁻³¹ kg ) These values define the system as per NCERT data. Formula: Momentum p = m v = 9.11 × 10⁻³¹ × 3.0 × 10⁶= 2.733 × 10⁻²⁴ kg m/s. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: lambda = h/p = frac6.63 × 10⁻³⁴².733 × 10⁻²⁴ approx 2.425 × 10⁻¹⁰ m = 0.2425 nm . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Oscillations and Waves, Topic: SHM, wave motion and superposition.

A bar magnet of magnetic moment 0.5 A m² is placed at a distance of 20 cm from its nter along its axis. Calculate the m

Given: A bar magnet of magnetic moment 0.5 A m² is placed at a distance of 20 cm from its nter along its axis. Calculate the magnetic field B at that point. (Take μ_0 = 4π × 10⁻⁷ T m A^{-1 ). These values define the system as per NCERT data. Formula: The magnetic field along the axis of a bar magnet is given by B = μ_0/4π 2m/r³. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Given: m = 0.5 A m², r = 20 cm = 0.2 m, μ_0/4π = 10⁻⁷ T m A^{-1 . Substitute: B = 10⁻⁷ × 2 × 0.5/(0.2)³ = 10⁻⁷ × 1/0.008 = 10⁻⁷ × 125 = 1.25 × 10⁻⁵ T . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Moving Charges and Magnetism and Magnetism and Matter, Topic: Magnetic field due to current loop, solenoid and magnetic dipole moment. Page number should be added only after verification from the.

A circular loop of radius 0.08 m with 60 turns carries a current of 0.75 A . What is the magnetic field at the nter? ( Î

Given: A circular loop of radius 0.08 m with 60 turns carries a current of 0.75 A . What is the magnetic field at the nter? ( μ_0 = 4 π × 10⁻⁷ T m/A ) These values define the system as per NCERT data. Formula: Magnetic field B = μ_0 N I/2 R. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: B = frac4 π × 10⁻⁷ × 60 × 0.752 × 0.08 = frac18 π × 10⁻⁶⁰.16 = 1.125 π × 10⁻⁴ approx 3.53 × 10⁻⁴ T . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Moving Charges and Magnetism and Magnetism and Matter, Topic: Magnetic field due to current loop, solenoid and magnetic dipole moment. Page number should be added only after verification from the.

A 5 kg particle moves with velocity v = 4 i m/s at r = -3 j m . What is the magnitude of its angular momentum about the

Given: A 5 kg particle moves with velocity v = 4 i m/s at r = -3 j m . What is the magnitude of its angular momentum about the origin? These values define the system as per NCERT data. Formula: L = r × p = beginvmatrix i & j & k 0 & -3 & 0 4 & 0 & 0 endvmatrix = k (0 × 0 - (-3) × 4) = 12 k kg m²/s. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Magnitude = 12 kg m²/s . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Units and Measurements and Physical World, Topic: Dimensional analysis and fundamental principles.

How much heat is required to raise the temperature of 0.5 moles of neon by 25 K at constant volume? (R = 8.31 J mol^{-1

Given: How much heat is required to raise the temperature of 0.5 moles of neon by 25 K at constant volume? (R = 8.31 J mol^{-1 K^{-1) These values define the system as per NCERT data. Formula: For monatomic gas, C_v = 3/2 R. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Q = μ C_v Δ T = 0.5 × 3/2 × 8.31 × 25 = 155.8125 J approx 155.8 J. Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Dual Nature, Atoms, Nuclei and Electronic Devices, Topic: Atomic structure, nuclear binding and semiconductor physics.

A 1250 kg car turns on a banked road ( θ = 15°, μ_s = 0.3 ) with radius 45 m . What is the maximum speed without slip

Given: A 1250 kg car turns on a banked road ( θ = 15°, μ_s = 0.3 ) with radius 45 m . What is the maximum speed without slipping? (Take g = 10 m/s², tan 15° approx 0.268 ) These values define the system as per NCERT data. Formula: Maximum speed: v_{max = sqrtrg μ_s + tanθ/1 - μ_s tanθ. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Numerator: μ_s + tanθ = 0.3 + 0.268 = 0.568 . Denominator: 1 - 0.3 × 0.268 = 1 - 0.0804 = 0.9196 . v_{max² = 45 × 10 × 0.568/0.9196 approx 450 × 0.6175 approx 277.875 . v_{max = sqrt277.875 approx 16.67 m/s . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Units and Measurements and Physical World, Topic: Dimensional analysis and fundamental principles.

A torque of 12 Nm is applied to a disk with moment of inertia 4 kg m² . What is its angular acceleration?

Given: A torque of 12 Nm is applied to a disk with moment of inertia 4 kg m² . What is its angular acceleration? These values define the system as per NCERT data. Formula: tau = I α. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: tau = 12 Nm, I = 4 kg m² . α = tau/I = 12/4 = 3 rad/s² . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Units and Measurements and Physical World, Topic: Dimensional analysis and fundamental principles.

A capillary tube of radius 0.65 mm is dipped in water ( S = 0.0727 N/m, rho = 1000 kg/m³, cos θ = 1 ). What is the cap

Given: A capillary tube of radius 0.65 mm is dipped in water ( S = 0.0727 N/m, rho = 1000 kg/m³, cos θ = 1 ). What is the capillary rise? (Take g = 9.8 m/s² ) These values define the system as per NCERT data. Formula: h = 2 S cos θ/rho g a. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: S = 0.0727 N/m, rho = 1000 kg/m³, g = 9.8 m/s², a = 0.65 × 10⁻³ m . h = frac2 × 0.0727 × 11000 × 9.8 × 0.65 × 10⁻³= 0.02285 m = 2.285 cm . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Units and Measurements and Physical World, Topic: Dimensional analysis and fundamental principles.