NEET 2016 Phase 2 · PhysicsDielectricsPrevious Year Question
A parallel-plate capacitor of area A, plate separation d and capacitance C is filled with four dielectric materials having dielectric constants k1, k2, k3 and k4 as shown in the figure below. If a single dielectric material is to be used to have the same capacitance C in this capacitor, then its dielectric constant k is given by
Answer: (C) 2/k = 3/(k1 + k2 + k3) + 1/k4. Answer: (c) Solution: Top half (d/2): k1,k2,k3 each over area A/3 are in parallel → effective k_top = (k1+k2+k3)/3.
- A.k = k1 + k2 + k3 + 3k4
- B.k = (2/3)(k1 + k2 + k3) + 2k4
- C.2/k = 3/(k1 + k2 + k3) + 1/k4✓
- D.1/k = 1/k1 + 1/k2 + 1/k3 + 3/(2k4)
Correct Answer
(C) 2/k = 3/(k1 + k2 + k3) + 1/k4
Solution & Explanation
Answer: (c) Solution: Top half (d/2): k1,k2,k3 each over area A/3 are in parallel → effective k_top = (k1+k2+k3)/3. This is in series with k4 (lower d/2). Series of two equal-thickness halves: 2/k = 1/k_top + 1/k4 = 3/(k1+k2+k3) + 1/k4. → option (c).
🎯
43,000+ questions in हिंदी & English · one-tap toggle
Open →📚Practice all NEET Physics PYQs chapter-wise →💡Don't get it? Learn the Electrostatic Potential And Capacitance concepts →Practice NEET 2016 Phase 2 Physics — free, with instant solutions
43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.
More NEET PYQ solutions
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:PhysPolar molecules are the molecules:PhysThe capacitance of a parallel plate capacitor with air as medium is 6 microF. With the introduction of a dielectric medium, the capacitance becomes 30 microF. The permittivity of the medium is: (eps0 = 8.85 × 10⁻¹² C² N⁻¹ m⁻²)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: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:PhysA uniform rod of mass 20 kg and length 5 m leans against a smooth vertical wall, making 60° with the wall; its lower end rests on a rough horizontal floor. The friction force exerted by the floor is: (g = 10 m/s²)