Tiêu đề 02. ELECTROSTATIC POTENTIAL AND CAPACITANCE.pdf ✅

02. ELECTROSTATIC POTENTIAL AND CAPACITANCE NEET PREPARATION (MEDIUM PHYSICS PAPER) Date: March 12, 2025 Dura on: 1:00:00 Total Marks: 180 INSTRUCTIONS INSTRUCTIONS PHYSICS 1. Assertion : Electric potential of earth is taken zero. Reason : No electric field exist on earth surface. (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 2. Assertion : The capacity of a given conductor remains same even if charge is varied on it. Reason : Capacitance depends upon dielectric medium as well as size and shape of conductor. (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 3. Calculate the area of the plates of a one farad parallel plate capacitor if separation between plates is and plates are in vacuum (1) (2) (3) (4) 4. A spherical drop of capacitance is broken into eight drops of equal radius. Then, the capac‐ itance of each small drop is (1) (2) (3) (4) 5. An electric field of is applied to an electric dipole at an angle of . The value of electric dipole moment is . The poten‐ tial energy of the electric dipole is found to be . Find the value of is (1) 25 (2) 35 (3) 50 (4) 15 6. Three uncharged capacitors of capacitances are connected as shown in the fig‐ ure. The potential at will be: (1) (2) (3) (4) 7. Two metal spheres of radii 0.01 and 0.02 are given a charge of 15 and 45 respec‐ tively. They are then connected by a wire. The fi‐ nal charge on the first sphere is ...... (1) (2) (3) (4) 8. When an additional charge of 2 C is given to a capacitor, energy stored in it is increased by 1 mm 18 × 10 8 m2 0.3 × 10 8 m2 1.3 × 10 8 m2 1.13 × 10 8 m2 1μF μF 1 2 μF 1 4 μF 1 8 8μF 2000 V /m 60 ∘ 10 −29Cm N × 10 −M N + M C1, C2 and C3 O V1+V2+V3 C1+C2+C3 V1C 2 1 +V2C 2 2 +V3C 2 3 C 2 1 +C 2 2 +C 2 3 V1C1+V2C2+V3C3 C1+C2+C3 V1V2V3 C1C2+C2C3+C3C1 m m mC mC ×10 −3C 40 30 20 10
21%, The original charge of the capacitor is (1) (2) (3) (4) 9. The number of ways one can arrange three iden‐ tical capacitors to obtain distinct effective capac‐ itances is (1) 8 (2) 6 (3) 4 (4) 3 10. In a Van de Graaff type generator, a spherical metal shell is to be at a . The dielec‐ tric stregth of the gas surrounding the electrode is . What is minimum radius of the spherical shell required? (1) (2) (3) (4) 11. small drops of the same size are charged to volt each. If they coalesce to form a single large drop, then its potential will be (1) (2) (3) (4) 12. A parallel plate capacitor has area sepa‐ rated by 3 dielectric slabs. Their relative permit‐ tivity is 2, 3, 6 and thickness is 0.4 , 0.6 , 1.2 respectively. The capacitance is (1) (2) (3) (4) 13. A parallel plate capacitor of capacitance is being charged by a voltage source whose po‐ tential is changing at the rate of 3 / . The con‐ duction current through the connecting wires, and the rate of change of the charge through the plates of the capacitor, would be, respectively. (1) (2) (3) (4) 14. Match the types of capacitors in Column I and expressions of capacitances in Column II. Column I Column II A Spherical capacitor P B Cylindrical capacitor Q C Parallel plate capacitor air filled R D Parallel plate capacitor with dielectric slab S (1) A - S, B - Q, C - R, D - P (2) A - S, B - R, C - P, D - Q (3) A - R, B - S, C - Q, D - P (4) A - S, B - R, C - Q, D - P 15. Assertion : Surface of a symmetrical conductor can be treated as equipotential surface. Reason : Charges can easily flow in a conductor. (1) Both Assertion and Reason are cor- rect and Reason is the correct explana- tion of the Assertion. (2) Both Assertion and Reason are cor- rect but Reason is not the correct explana- tion of the Assertion. (3) Assertion is cor- rect but Reason is incorrect. (4) Assertion is incor- rect but reason is correct. 16. A small oil drop of mass is hanging in at rest between two plates separated by 1 having a potential difference of 500 V. The charge on the drop is ......... (1) (2) (3) (4) 17. A point charge is placed inside a conducting spherical shell of inner radius 2 and outer ra‐ dius 3 at a distance of from the center of the shell. Find the electric potential at the center of the shell. (1) (2) (3) (4) 18. A hollow charged metal sphere has radius . If the potential difference between its surface and a point at distance from the centre is , then the electric intensity at distance from the centre is (1) (2) (3) (4) 30 C 40 C 10 C 20 C 1.5 × 10 6V 3 × 10 6V m−1 40 cm 30 cm 50 cm 20 cm N V V N 1/3 V /N NV V N 2/3 2m2 mm mm mm 11 × 10 −8 Farad 5 × 10 −8 Farad 10 × 10 −8 Farad 2.95 × 10 −8 Farad 20μF V s Zero, 60μA 60μA, 60μA 60μA, Zero Zero, zero ε0KA d ε0A d 2πε0l ln( ) r2 r1 4πε0r1r2 r1∼r2 10 −6kg mm (g = 10ms −2) 2 × 10 −9C 2 × 10 −11C 2 × 10 −6C 2 × 10 −8C q R R R 1 4πε0 q 2R 1 4πε0 4q 3R 1 4πε0 5q 6R 1 4πε0 2q 3R r 3r V 3r V 6r V 4r V 3r V 2r