CUET Physics Practice Quiz 2
Welcome to this CUET Physics Practice Quiz, designed to help you sharpen your problem-solving skills and deepen your understanding of key concepts in physics. This set of 20 medium-difficulty questions covers a range of topics including electrostatics, magnetism, optics, modern physics, and thermodynamics.
Each question is crafted to mirror the style and rigor of the CUET examination, focusing on conceptual clarity and application. Read each question carefully, choose the best answer, and use the detailed explanations provided to reinforce your learning. Good luck!
Q1. Two charges of +4 µC and -2 µC are placed 30 cm apart in a vacuum. The magnitude of the electrostatic force between them is approximately:
Using Coulomb's law, F = k *
Q2. A wire of length 1 m is moving with a velocity of 5 m/s perpendicular to a magnetic field of 0.2 T. The induced EMF across the ends of the wire is:
The motional EMF is given by E = B * l * v = 0.2 T * 1 m * 5 m/s = 1 V.
Q3. In a Young's double-slit experiment, the fringe width is 0.5 mm. If the distance between the slits is doubled, the new fringe width will be:
Fringe width (β) is inversely proportional to the slit separation (d). If d is doubled, β becomes half, so the new fringe width is 0.25 mm.
Q4. The work function of a metal is 2.5 eV. The maximum kinetic energy of photoelectrons emitted when light of wavelength 400 nm falls on it is approximately: (h = 6.63 x 10^-34 Js, c = 3 x 10^8 m/s, 1 eV = 1.6 x 10^-19 J)
The energy of the photon is E = hc/λ = (6.63 x 10^-34 * 3 x 10^8) / (400 x 10^-9) = 4.97 x 10^-19 J ≈ 3.1 eV. The maximum kinetic energy is E - φ = 3.1 eV - 2.5 eV = 0.6 eV.
Q5. A convex lens has a focal length of 20 cm. The power of the lens is:
Power (P) is the reciprocal of focal length in meters. P = 1 / 0.20 m = +5 D. The sign is positive for a convex lens.
Q6. In an LCR series circuit, at resonance, the impedance of the circuit is equal to:
At resonance, the inductive reactance equals the capacitive reactance, and they cancel each other out. The impedance is then purely resistive and equals the resistance of the circuit.
Q7. The half-life of a radioactive substance is 10 days. The time taken for 75% of the sample to decay is:
After one half-life (10 days), 50% remains. After two half-lives (20 days), 25% remains, meaning 75% has decayed.
Q8. A Carnot engine operates between temperatures 500 K and 300 K. Its efficiency is:
The efficiency of a Carnot engine is 1 - (T_cold / T_hot) = 1 - (300/500) = 1 - 0.6 = 0.4, or 40%.
Q9. The de Broglie wavelength of an electron accelerated through a potential difference of 100 V is approximately:
The de Broglie wavelength is given by λ = h / √(2mE), where E = eV. For V = 100 V, λ ≈ 1.227 / √V nm = 1.227 / 10 = 0.123 nm.
Q10. A current of 2 A flows through a resistor of 10 Ω for 5 minutes. The heat produced in the resistor is:
Heat produced (H) = I^2 * R * t = (2)^2 * 10 * (5 * 60) = 4 * 10 * 300 = 12000 J.
Q11. The electric potential at a point 0.5 m away from a point charge of 2 µC is: (k = 9 x 10^9 Nm^2/C^2)
The electric potential V = kQ/r = (9 x 10^9 * 2 x 10^-6) / 0.5 = 3.6 x 10^4 V.
Q12. In a transformer, the number of turns in the primary and secondary coils are 200 and 1000, respectively. If the input voltage is 50 V, the output voltage is:
The transformer equation is V_s / V_p = N_s / N_p. So, V_s = V_p * (N_s / N_p) = 50 * (1000/200) = 250 V.
Q13. The refractive index of a medium is 1.5. The speed of light in this medium is:
The speed of light in a medium is v = c / n = (3 x 10^8) / 1.5 = 2 x 10^8 m/s.
Q14. A body of mass 2 kg is moving with a velocity of 3 m/s. Its kinetic energy is:
Kinetic energy (KE) = 0.5 * m * v^2 = 0.5 * 2 * (3)^2 = 9 J.
Q15. The energy of a photon of frequency 5 x 10^14 Hz is approximately: (h = 6.63 x 10^-34 Js)
The energy of a photon is E = h * f = 6.63 x 10^-34 * 5 x 10^14 = 3.315 x 10^-19 J ≈ 3.3 x 10^-19 J.
Q16. The magnetic field at the center of a circular coil of radius 10 cm carrying a current of 5 A is: (µ0 = 4π x 10^-7 Tm/A)
The magnetic field at the center of a circular coil is B = µ0 * I / (2 * r) = (4π x 10^-7 * 5) / (2 * 0.1) = 3.14 x 10^-5 T.
Q17. In a p-n junction diode, the depletion region is formed due to the:
The depletion region is formed due to the diffusion of electrons and holes across the junction, which leaves behind immobile ions.
Q18. The rms value of an AC voltage with a peak value of 100 V is:
The rms value is V_rms = V_peak / √2 = 100 / 1.414 ≈ 70.7 V.
Q19. A body is projected vertically upward with a velocity of 20 m/s. The maximum height reached is: (g = 10 m/s^2)
The maximum height is h = v^2 / (2g) = (20)^2 / (2 * 10) = 400 / 20 = 20 m.
Q20. The capacitance of a parallel plate capacitor is 10 µF. If the distance between the plates is doubled, the new capacitance will be:
Capacitance is inversely proportional to the distance between the plates. If the distance is doubled, the capacitance is halved, so the new capacitance is 5 µF.