NEET 2023 Phase 1 · PhysicsDipole torquePrevious Year Question
An electric dipole is placed at an angle of 30° with an electric field of intensity 2 × 10⁵ N C⁻¹. It experiences a torque equal to 4 N m. Calculate the magnitude of charge on the dipole, if the dipole length is 2 cm.
Answer: (D) 2 mC. Answer: (d) Solution: Torque on a dipole in a uniform field: τ = pE sinθ, where p = qL.
- A.8 mC
- B.6 mC
- C.4 mC
- D.2 mC✓
Correct Answer
(D) 2 mC
Solution & Explanation
Answer: (d) Solution: Torque on a dipole in a uniform field: τ = pE sinθ, where p = qL. So τ = qLE sinθ. Given: τ = 4 N m, E = 2 × 10⁵ N C⁻¹, L = 2 cm = 0.02 m, θ = 30° → sin30° = 0.5. Solve for q: q = τ / (L E sinθ) = 4 / [(0.02)(2 × 10⁵)(0.5)] q = 4 / (2000) = 2 × 10⁻³ C = 2 mC. Hence the charge magnitude is 2 mC.
🎯
43,000+ questions in हिंदी & English · one-tap toggle
Open →📚Practice all NEET Physics PYQs chapter-wise →💡Don't get it? Learn the Electric Charges And Fields 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
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:PhysAn electric dipole is placed at an angle of 30° with an electric field of intensity 2 × 10⁵ N/C. It experiences a torque equal to 4 N·m. The charge on the dipole, if the dipole length is 2 cm, isPhysA dipole is placed in a non-uniform electric field as shown. In which direction will it move?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: