Tiêu đề 03. CURRENT ELECTRICITY(H).pdf ✅

NEET REVISION (1) 2 all the time (2) oscillates between 1 and 2 (3) 1 all the time (4) At , and reduces to 1 finally 8. At what value of the resistance in the circuit shown in the figure will the total resistance be‐ tween points and be independent of the number of cells? If , then the value of will be [Q356997] (1) (2) (3) (4) 9. While connecting 5 cells in a battery in series, in a tape recorder, by mistake one cell is connected with reverse polarity. If the effective load resis‐ tance is of load is and internal resis‐ tance of each cell is one ohm and emf , the current delivered by the battery is [Q356887] (1) (2) (3) (4) 10. Find the value of resistor to be connected be‐ tween & , so that the resistance of the entire circuit between & does not change with the number of elementary sets. [Q356996] (1) (2) (3) (4) 11. In the part of a circuit shown in the figure, the potential difference between points and will be: [Q357405] (1) (2) (3) (4) 12. In a meter bridge as shown in the figure it is given that resistance and that the balance is obtained at a distance 39.5 from end (by Jockey ). After interchanging the re‐ sistances and a new balance point is found at a distance from end . What are the values of and ? [Q357275] (1) and (2) and 60 (3) and 39.5 (4) and 60.5 13. In an experiment to determine the temperature coefficient of resistance of a conductor, a coil of wire is immersed in a liquid. It is heated by an external agent. A meter bridge set up is used to determine resistance of the coil at different temperatures. The balancing points measured at temperatures and are and respectively. If the standard re‐ sistance taken out is in both trials, the temperature coefficient of the coil is [Q357279] (1) (2) (3) (4) 14. In a metre-bridge when a resistance in the left gap is and unknown resistance in the right gap, the balance length is found to be On shunting the unknown resistance with the balance length changes by [Q357272] (1) (2) (3) (4) 15. Two electric bulbs rated and are glowing at full power, when used in parallel with a battery of emf and internal resistance . The maximum number of bulbs that can be connected in the circuit when glowing at full power, is [Q357170] (1) 6 (2) 4 (3) 2 (4) 8 16. The potential difference across the terminals of a battery is when current is drawn and when current is drawn. The emf and the internal resistance of the battery are [Q356895] mA mA mA mA t = 0 I = 2 mA mA A B R = (√3 + 1)Ω x 1 Ω 5 Ω 2 Ω 7 Ω 7 Ω 24 ohm 2 V 0.1 A 0.5 A 0.3 A 0.4 A C D A B R (√2 − 1) R (√3 − 1) 2R 3R (VG − VH) G H 0 V 15 V 7 V 3 V Y = 12.5 Ω cm A J X Y l2 A X l2 19.5 Ω 39.5 Ω 8.16 Ω cm 8.16 Ω cm 19.15 Ω cm X X t1 = 0 ∘C t2 = 100 ∘C 50 cm 60 cm S = 4 Ω 0.05 ∘C −1 0.02 ∘C −1 0.005 ∘C −1 2.0 ∘C −1 2 Ω 40 cm. 2 Ω, 62.5 cm 22.5 cm 20 cm 65 cm 50 W 100 V 120 V 10 Ω 50 V 11 A 60 V 1 A
NEET REVISION (1) (2) (3) (4) 17. Consider a spherical shell having inner radius and outer radius . If the resistivity of the mate‐ rial is then find the equivalent resistance be‐ tween inner and outer surface. [Q356924] (1) (2) (3) (4) 18. The ratio of the amounts of heat developed in the four arms of a balance Wheatstone bridge, when the arms have resistances and respectively is [Q357363] (1) (2) (3) (4) 19. A uniform wire of resistance and length is cut into four equal parts, each of length , which are then connected in parallel combina‐ tion. The effective resistance of the combination will be [Q356951] (1) (2) (3) (4) 20. In the given figure, equivalent resistance be‐ tween and will be [Q356929] (1) (2) (3) (4) 21. The resistance per centimeter of a meter bridge wire is , with resistance in left gap. Balancing length from left end is at with resistance in right gap. Now the wire is re‐ placed by another wire of resistance per cen‐ timeter. The new balancing length for same will be at [Q357282] (1) (2) (3) (4) 22. The equivalent resistance between and is [Q356943] (1) (2) (3) (4) 23. Each of three resistors in figure has a resistance of and can dissipate a maximum of 36 without becoming excessively heated. What is the maximum power the circuit can dissipate? [Q357112] (1) (2) (3) (4) 24. A ring is made of a wire having a resistance . Find the ratio the lengths at which a current carrying conductor should be connected so that the resistance of the sub circuit be‐ tween these points is equal to . [Q356932] (1) (2) (3) (4) 25. Three cells are connected as shown in the fig‐ ure. Find the equivalent emf of the combination [Q356888] (1) (2) (3) (4) 26. Find the reading of the ammeters connected as shown in the network. 62 V , 2 Ω 63 V , 1 Ω 61 V , 1 Ω 64 V , 2 Ω a b ρ ρ(a+b) 4πab ρ(b−a) 4πab ρ 4πb ρ b P = 100 Ω, Q = 10 Ω, R = 300 Ω S = 30 Ω 3 : 30 : 1 : 10 30 : 3 : 10 : 1 30 : 10 : 1 : 3 30 : 1 : 3 : 10 R L L/4 R 4R R 4 R 16 A B Ω 13 11 Ω 14 9 Ω 1 14 Ω 3 11 r XΩ 40 cm 25 Ω 2 r 20 cm 40 cm 80 cm 10 cm A B 25 Ω 18 Ω 27 Ω 19 Ω 2.4 Ω W 25 W 54 W 63 W 34 W R0 = 12Ω l 2 l2 R Ω 8 3 = l1 l2 5 8 = l1 l2 1 3 = l1 l2 3 8 = l1 l2 1 2 V 1 3 V 1 6 V 1 2 1V A1
NEET REVISION [Q357208] (1) (2) (3) (4) 27. A main supply of e.m.f. 220 is connected across a storage battery of e.m.f. 200 through a resistance of . The battery terminals are con‐ nected to an external resistance . The mini‐ mum value of , so that a current passes through the battery to charge it is :- [Q357407] (1) Zero (2) (3) (4) 28. Charge passing through a conductor of cross- section area is given by in coulomb, where is in sec‐ ond. What is the value of drift velocity at ? (Given, ) [Q357012] (1) (2) (3) (4) 29. A portion of length is cut out of a conical solid wire. The two ends of this portion have cir‐ cular cross-sections of and radii. It is connected lengthwise to a circuit and a cur‐ rent is flowing in it. The resistivity of the mate‐ rial of the wire Calculate the voltage devel‐ oped across it. [Q357059] (1) (2) (3) (4) 30. Wheatstone bridge principle is used of measure the specific resistance of given wire, having length , radius . If is the resistance of wire, then specific resistance is . If the length of the wire gets doubled then the value of specific resistance will be : [Q357357] (1) (2) (3) (4) 31. A wire of length and resistance is di‐ vided into 10 equal parts. The first 5 parts are connected in series while the next 5 parts are connected in parallel. The two combinations are again connected in series. The resistance of this final combination is: [Q356940] (1) (2) (3) (4) 32. In the potentiometer experiment the ratio of and is equal to 2. If the balancing length , when the switch is closed and is open. Find the bal ancing length when is open and is closed. [Q357341] (1) (2) (3) (4) 33. In a metre bridge experiment resistances are connected as shown in the figure. Initially resis‐ tance and the netural point is at 60 from . Now an unknown resistance is connected in series to and the new position of the neutral point is at 80 from . The value of unknown resistance is- [Q357281] (1) (2) (3) (4) 34. For a cell,the graph between the potential dif‐ ference across terminals of the cell and the current drawn from the cell is shown in the figure. Then, (a) of the cell is (b) of the cell is (c) the internal resistance of cell is (d) The internal resistance of the cell is Choose the correct statements. [Q356905] (1) (2) (3) (4) 35. In the circuit shown in Fig. Intially, capacitor is charged to a potential of . The 2 A 5 A 8 A 9 A d. c V V 1Ω ‘R′ ‘R′ 11Ω 9Ω 7Ω A = 0.3 m2 q = 3t 2 + 5t + 2 t t = 2s n = 2 × 10 25/m2 0.77 × 10 −5 m/s 1.77 × 10 −5 m/s 2.08 × 10 5 m/s 0.57 × 10 −5 m/s L r1 r2(r1 > r2) I ρ. ρLI πr1 ρLI πr2 ρLI πr1r2 ρLI πr 2 1 (S1) L r X ; S1 = X ( ) πr 2 L S1 2 S1 S1 2 S1 4 l 100 Ω 26 Ω 52 Ω 55 Ω 60 Ω ε1 ε2 l1 = 10cm S1 S2 S1 S2 10 cm 5 cm 1 5 cm 20 cm P = 4Ω N cm A R P cm A R Ω 33 5 6 Ω Ω 20 3 7 Ω (V ) I emf 2.5V emf 2.0V 0.5Ω 0.4Ω a, c a, d b, c b, d C1 = 2C2. C1 V