NEET 2023 Phase 1 · PhysicsRMS speedPrevious Year Question
The temperature of a gas is −50 °C. To what temperature should the gas be heated so that the rms speed is increased by 3 times?
Answer: (B) 3295 °C. Correct Answer (B): 3295 °C Since v_rms ∝ √T, the temperature must be scaled by the square of the speed factor.
- A.669 °C
- B.3295 °C✓
- C.3097 K
- D.223 K
Correct Answer
(B) 3295 °C
Solution & Explanation
Correct Answer (B): 3295 °C Since v_rms ∝ √T, the temperature must be scaled by the square of the speed factor. "Increased by 3 times" is taken to mean the increase is 3× the original, so the final speed is 4× the initial (original + 3× original). Hence T_f/T_i = 4² = 16. With T_i = −50 °C = 223 K, T_f = 16 × 223 = 3568 K = 3295 °C, matching the official key.
🎯
43,000+ questions in हिंदी & English · one-tap toggle
Open →📚Practice all NEET Physics PYQs chapter-wise →💡Don't get it? Learn the Kinetic Theory concepts →Practice NEET 2023 Phase 1 Physics — free, with instant solutions
43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.
More NEET PYQ solutions
PhysA flask contains argon and chlorine in the ratio of 2 : 1 by mass. The temperature of the mixture is 27 °C. The ratio of root mean square speeds of the molecules of the two gases (v_rms^Ar / v_rms^Cl) is: (Atomic mass of argon = 40.0 u and molecular mass of chlorine = 70.0 u)PhysAt what temperature will the rms speed of oxygen molecules become just sufficient for escaping from the Earth's atmosphere? (Given: mass of an oxygen molecule m = 2.76 × 10⁻²⁶ kg, Boltzmann constant k_B = 1.38 × 10⁻²³ J K⁻¹, escape speed = 11200 ms⁻¹)PhysThe molecules of a given mass of a gas have r.m.s. velocity of 200 ms⁻¹ at 27 °C and 1.0 × 10⁵ Nm⁻² pressure. When the temperature and pressure of the gas are respectively 127 °C and 0.05 × 10⁵ Nm⁻², the r.m.s. velocity of its molecules in ms⁻¹ is:PhysAn electric dipole with dipole moment 5 × 10⁻⁶ C·m is aligned with the direction of a uniform electric field of magnitude 4 × 10⁵ N/C. The dipole is then rotated through an angle of 60° with respect to the electric field. The change in the potential energy of the dipole is:PhysTwo identical charged conducting spheres A and B have their centres separated by a certain distance. Charge on each sphere is q and the force of repulsion between them is F. A third identical uncharged conducting sphere is brought in contact with sphere A first and then with B and finally removed from both. New force of repulsion between spheres A and B (radii negligible vs separation, treated as point charges) is best given as:PhysThe plates of a parallel plate capacitor are separated by d. Two slabs of different dielectric constant K1 and K2 with thickness 3d/8 and d/2 respectively are inserted in the capacitor. Due to this, the capacitance becomes two times larger than when there is nothing between the plates. If K1/K2 = 1.25, the value of K1 is:PhysA sphere of radius R is carved out of a uniform solid sphere of radius 2R (internally tangent, so its centre is at distance R from the big centre). The ratio of the moment of inertia of the small sphere to that of the remaining part, both about the Y-axis through the big sphere's centre, is:PhysThe Sun rotates once in 27 days. If it expanded to twice its present radius (uniform-density sphere, no external influence), its new period would be about: