Current Electricity PYQs Set 12 (PDF)

Set 12 of 25 · Questions 331-360 of 723

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Mere Teacher · Previous Year Questions JEE Main Physics · Current Electricity · Set 12 (Q331-360)
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331. $Five identical resistors each of resistance R = 1500Ω are connected to a 300 V battery as shown in the circuit. The reading of the ideal ammeter A is$ (1) $\frac{1}{5} A$ (2) $\frac{3}{5} A$ (3) $\frac{2}{5} A$ (4) $\frac{4}{5} A$ 332. $A current of 3 amp. flows through the 2Ω resistor shown in the circuit. The power dissipated in the 5Ω resistor is$ (1) $1 watt$ (2) $5 watt$ (3) $4 watt$ (4) $2 watt$ 333. $The value of unknown resistance (x) for which the potential difference between B and D will be zero in the arrangement shown, is:$ (1) $3Ω$ (2) $42Ω$ (3) $9Ω$ (4) $6Ω$ 334. $What is the current through the battery in the circuit shown below$ (1) $1.5 A$ (2) $0.5 A$ (3) $0.25 A$ (4) $1.0 A$ 335. $The meter bridge shown in the balance position with \frac{P}{Q} = \frac{l _{1}}{l _{2}} . If we now interchange the positions of galvanometer and cell, will the bridge work? If yes, what will be balanced condition? [NEET 2019]$ (1) $Yes, \frac{P}{Q} = \frac{l _{2} - l _{1}}{l _{2} + l _{1}}$ (2) $No, no null point$ (3) $Yes, \frac{P}{Q} = \frac{l _{2}}{l _{1}}$ (4) $Yes, \frac{P}{Q} = \frac{l _{1}}{l _{2}}$ 336. $n identical resistance are taken in which \frac{n}{2} resistors are joined in series in the left gap and the remaining \frac{n}{2} resistances are joined in parallel in the right gap of a metre bridge. Balancing length in cm is.$ (1) $100 \cdot \frac{n ^{2}}{n ^{2} + 4}$ (2) $100 \cdot \frac{n ^{2}}{n ^{2} + 1}$ (3) $400 \cdot \frac{1}{n ^{2} + 4}$ (4) $400 \cdot \frac{1}{n ^{2} + 1}$ 337. $The resistances in the two arms of the meter bridge are 5 Ω and RΩ respectively When the resistance R is shunted with an equal resistance, the new balance point is at 1.6 l_{1} . The resistance R is$ (1) $10 Ω$ (2) $15 Ω$ (3) $20 Ω$ (4) $25 Ω$ 338. $A battery of 6 V is connected to the circuit as shown below. The current I drawn from the battery is$ (1) $1 A$ (2) $2 A$ (3) $\frac{6}{11} A$ (4) $\frac{4}{3} A$ 339. $A potentiometer wire has length 4 m and resistance 8 Ω . The resistance that must be connected in series with the wire and an accumulator of e.m.f. 2 V, so as to get a potential gradient 1 mV per cm on the wire is$ (1) $44 Ω$ (2) $48 Ω$ (3) $32 Ω$ (4) $40 Ω$ 340. $In steady state, a capacitor of capacitance 2 μF is charged to 4 μC, as shown in figure. If the internal resistance of the cell is 0.5Ω, then the emf of the cell is$ (1) $4 V$ (2) $5 V$ (3) $2.5 V$ (4) $2 V$ 341. $See the electrical circuit shown in this figure. Which of the following equations is a correct equation for it?$ (1) $ε_{1} - (i_{1} + i_{2})R - i_{1} r_{1} = 0$ (2) $ε_{2} - i_{2} r_{2} - ε_{1} - i_{1} r_{1} = 0$ (3) $- ε_{2} - (i_{1} + i_{2})R + i_{2} r_{2} = 0$ (4) $ε_{1} - (i_{1} + i_{2})R + i_{1} r_{1} = 0$ 342. $On interchanging the resistances, the balance point of a meter bridge shifts to the left by 10 cm. The resistance of their series combination is 1KΩ. How much was the resistance on the left slot before interchanging the resistances?$ (1) $550$ (2) $910$ (3) $990$ (4) $505$ 343. $Two bars of equal resistivity ρ and radii 'r' and '2r' are kept in contact as shown. An electric current I is passed through the bars. Which one of the following is correct$ (1) $Heat produced in bar (a) is 2 times the heat produced in bar (b)$ (2) $Electric field in both halves is equal$ (3) $Current density across AB is double that across BC.$ (4) $Potential difference across BC is 4 times that across AB.$ 344. $In the given potentiometer circuit arrangement, the balancing length AC is measured to be 250 cm. When the galvanometer connection is shifted from point (1) to point (2) in the given diagram, the balancing length becomes 400 cm. The ratio of the emf of two cells, \frac{ϵ _{1}}{ϵ} is$ (1) $\frac{5}{3}$ (2) $\frac{8}{5}$ (3) $\frac{4}{3}$ (4) $\frac{3}{2}$ 345. $An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and resistance 5Ω . The value of R, to give a potential difference of 5 mV across 10 cm of potentiometer wire is:$ (1) $490Ω$ (2) $480Ω$ (3) $395Ω$ (4) $495Ω$ 346. $In the circuit shown the cells A and B have negligible resistances. For V_{A} = 12V, R_{1} = 500Ω and R = 100Ω the galvanometer (G) shows no deflection. The value of V_{B} is:$ (1) $4V$ (2) $2V$ (3) $12V$ (4) $6V$ 347. $The resistance in following circuit are R_{1} = R_{2} = R_{3} = 6.0Ω . The emf of the battery is 12 V . When switch S is closed, the potential across resistance R_{1} is changed by an amount.$ (1) $- 2 V$ (2) $+ 2 V$ (3) $- 4 V$ (4) $+ 4 V$ 348. $The net resistance of the circuit between A and B is$ (1) $\frac{8}{3} Ω$ (2) $\frac{14}{3} Ω$ (3) $\frac{16}{3} Ω$ (4) $\frac{22}{3} Ω$ 349. $Two metal wires of identical dimension are connected in series. If σ_{1} and σ_{2} are the conductivities of the metal wires respectively, the effective conductivity of the combination is:$ (1) $\frac{σ _{1} + σ _{2}}{2 σ _{1} σ _{2}}$ (2) $\frac{σ _{1} + σ _{2}}{σ _{1} σ _{2}}$ (3) $\frac{σ _{1} σ _{2}}{σ _{1} + σ _{2}}$ (4) $\frac{2 σ _{1} σ _{2}}{σ _{1} + σ _{2}}$ 350. $A wire of resistance R is bent into an equilateral triangle and an identical wire is bent into a square. The ratio of resistance between the two end points of an edge of the triangle to that of the square is Options$ (1) $8/9$ (2) $27/32$ (3) $32/27$ (4) $9/8$ 351. $In a meter bridge, the wire of length 1 m has a non-uniform cross-section such that, the variation \frac{dR}{dl} of its resistance R with length I is \frac{dR}{dl} \propto \frac{1}{l} . Two equal resistances are connected as shown in the figure. The galvanometer has zero deflection when the jockey is at point P What is the length AP ?$ (1) $0.2 m$ (2) $0.3 m$ (3) $0.25 m$ (4) $0.35 m$ 352. $A wire of uniform resistance λΩ / m is bent into a circle of radius r and another piece of wire with length 2 r is connected between points A and B (AOB) as shown in figure. The equivalent resistance between points A and B is____Ω .$ (1) $\frac{3 πλr}{8}$ (2) $\frac{6 πλr}{3 π + 16}$ (3) $2 πλr$ (4) $(π + 1) 2 rλ$ 353. $Determine the charge on the capacitor in the following circuit:$ (1) $60 μC$ (2) $2 μC$ (3) $10 μC$ (4) $200 μC$ 354. $The meter bridge shown is in balance position with \frac{P}{Q} = \frac{l _{1}}{l _{2}} . If we now interchange the positions of galvanometer and cell, will the bridge work?. If yes, what will be balanced condition?$ (1) $yes, \frac{P}{Q} = \frac{l _{2} - l _{1}}{l _{2} + l _{1}}$ (2) $no, no null point$ (3) $yes, \frac{P}{Q} = \frac{l _{2}}{l _{1}}$ (4) $yes, \frac{P}{Q} = \frac{l _{1}}{l _{2}}$ 355. $In the circuit shown in the figure, if the potential at point A is taken to be zero, the potential at point B is$ (1) $+ 1 V$ (2) $- 1 V$ (3) $+ 2 V$ (4) $- 2 V$ 356. $In the given circuit the cells have zero internal resistance. The currents (in Amperes) passing through resistance R_{1} and R_{2} respectively, are:$ (1) $1, 2$ (2) $2, 2$ (3) $0.5, 0$ (4) $0, 1$ 357. $A wire of length 25 m and cross-sectional area 5 mm^{2} having resistivity of 2 \times 10^{- 6} Ω m is bent into a complete circle. The resistance between diametrically opposite points will be$ (1) $100Ω$ (2) $2.5Ω$ (3) $12.5Ω$ (4) $50Ω$ 358. $For the given circuit the current through battery of 6 V just after closing the switch^{4} S' will be .......... A.$ 359. $In the given figure, the value of V_{0} will be ____V.$ 360. $Two resistance of 100Ω and 200Ω are connected in series with a battery of 4 V and negligible internal resistance. A voltmeter is used to measure voltage across 100Ω resistance, which gives reading as 1 V . The resistance of voltmeter must be____Ω .$