Current Electricity PYQs Set 21 (PDF)

Set 21 of 25 · Questions 601-630 of 723

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Mere Teacher · Previous Year Questions JEE Main Physics · Current Electricity · Set 21 (Q601-630)
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601. $The value of current in the 6Ω resistance is:$ (1) $4A$ (2) $8A$ (3) $10A$ (4) $6A$ 602. $The equivalent resistance between the points A and B will be (each resistance is 15Ω)$ (1) $10Ω$ (2) $40Ω$ (3) $30Ω$ (4) $8Ω$ 603. $The magnitude and direction of the current in the following circuit is [NEET 2023]$ (1) $0.5 A from A to B through E$ (2) $5/9 A from A to B through E$ (3) $1.5 A from B to A through E$ (4) $0.2 A from B to A through E$ 604. $A wire, 10 m long, has a resistance of 40Ω . It is connected in series with a resistance box of resistance R and a 2 V storage cell. If the potential gradient along the wire is 0.1 mV / cm, then the value of R is$ (1) $260Ω$ (2) $760Ω$ (3) $960Ω$ (4) $1060Ω$ 605. $the switch S_{1} is closed at time t = 0 and the switch S_{2} is kept open. At some later time (t_{0}), the switch S_{1} is opened and S_{2} is closed. the behaviour of the current I as a function of time 't' is given by:$ (1) (2) (3) (4) 606. $The resistance per centimeter of a meter bridge wire is r, with XΩ resistance in left gap. Balancing length from left end is at 40 cm with 25Ω resistance in right gap. Now the wire is replaced by another wire of 2r resistance per centimeter. The new balancing length for same settings will be at$ (1) $20 cm$ (2) $10 cm$ (3) $80 cm$ (4) $40 cm$ 607. $A circuit contains an ammeter, a batter of 30 V and a resistance 40.8 ohm all connected in series. If the ammeter has a coil of resistance 480 ohm and a shunt of 20 ohm, the reading in the ammeter will be:$ (1) $0.25 A$ (2) $2A$ (3) $1 A$ (4) $0.5 A$ 608. $In the given circuit diagram, the currents, I_{1} = - 0.3A, I_{4} = 0.8 A and I_{5} = 0.4 A, are flowing as shown. The currents I_{2}, I_{3} and I_{6} respectively, are:$ (1) $1.1 A, 0.4 A, 0.4 A$ (2) $-0.4 A, 0.4 A, 1.1 A$ (3) $0.4 A, 1.1 A, 0.4 A$ (4) $1.1 A, -0.4 A, 0.4 A$ 609. $If power dissipated in the 9 Ω resistor in the circuit shown is 36 watt, the potential difference across the 2 Ω resistor is$ (1) $4 volt$ (2) $8 volt$ (3) $10 volt$ (4) $2 volt$ 610. $The potential difference between A and B in the following figure is$ (1) $24 V$ (2) $14 V$ (3) $32 V$ (4) $48 V$ 611. $When a potentiometer is connected between the points A and B as shown in the circuit, balance point is obtained at 64 cm . When it is connected between A and C, the balance point is 8 cm . If the potentiometer is connected between B and C the balance point will be$ (1) $8 cm$ (2) $56 cm$ (3) $64 cm$ (4) $72 cm$ 612. $In the circuit diagram, heat produces in R, 2 R and 1.5 R are in the ratio of$ (1) $4 : 2 : 3$ (2) $8 : 4 : 27$ (3) $2 : 4 : 3$ (4) $27 : 8 : 4$ 613. $A teacher in his physics laboratory allotted an experiment to determine the resistance (G) of a galvanometer. Students took the observations for \frac{1}{3} deflection in the galvanometer. Which of the below is true for measuring value of G?$ (1) $\frac{1}{3} deflection method cannot be used for determining the resistance of th galvanometer.$ (2) $\frac{1}{3} deflection method can be used and in this case the G equals to twice the value of shunt resistance(s).$ (3) $\frac{1}{3} deflection method can be used and in this case, the G equals to three times the value of shunt resistance(s)$ (4) $\frac{1}{3} deflection method can be used and in this case the G value equals to the shunt resistance(s).$ 614. $The combination of two identical cells, whether connected in series or parallel combination provides the same current through an external resistance of 2 Ω . The value of internal resistance of each cell is:$ (1) $2 Ω$ (2) $4 Ω$ (3) $6 Ω$ (4) $8 Ω$ 615. $A galvanometer having coil resistance 10Ω shows a full scale deflection for a current of 3 mA . For it to measure a current of 8 A, the value of the shunt should be:$ (1) $3\times 1 0^{- 3} Ω$ (2) $4.85\times 1 0^{- 3} Ω$ (3) $3.75\times 1 0^{- 3} Ω$ (4) $2.75\times 1 0^{- 3} Ω$ 616. $Two square shaped metal plates of A and B of same thickness (t) and of same material are connected as shown in the figure. The side of B is twice that of A. If the resistance of A and B are R_{A} and R_{B} respectively then \frac{R _{A}}{R _{B}} is$ (1) $\frac{1}{2}$ (2) $2$ (3) $1$ (4) $4$ 617. $The actual value of resistance R, shown in the figure is 30Ω . This is measured in an experiment as shown using the standard formula R = \frac{V}{I}, where V and I are the reading of the voltmeter and ammeter, respectively. If the measured value of R is 5 % less, then the internal resistance of the voltmeter is:$ (1) $600Ω$ (2) $570Ω$ (3) $35Ω$ (4) $350Ω$ 618. $Consider a thin square sheet of side L and thickness t, made of a material of resitivity ρ. The resistance between two opposite faces, shown by the shaded areas in the figure is:$ (1) $directly proportional to L$ (2) $directly proportional to t$ (3) $independent of L$ (4) $independent of t$ 619. $Three voltmeters A, B and C having resistances R, 1.5 R and 3R respectively are used in a circuit as shown. When a P.D. is applied between X and Y, the reading of the voltmeters are V_{1}, V_{2} and V_{3} respectively. Then$ (1) $V_{1} = V_{2} = V_{3}$ (2) $V_{1} < V_{2} = V_{3}$ (3) $V_{1} > V_{2} > V_{3}$ (4) $V_{1} > V_{2} = V_{3}$ 620. $A wire of length 3 m connected in the left gap of a meter-bridge balances 8Ω resistance in the right gap at a point, which divides the bridge wire in the ratio 3 : 2 . The length of the wire corresponding to resistance of 1Ω is$ (1) $1 m$ (2) $0.75 m$ (3) $0.5 m$ (4) $0.25 m$ 621. $Six similar bulbs are connected as shown in the figure with a DC source of emf E and zero internal resistance. The ratio of power consumption by the bulbs when (i) all are glowing and (ii) in the situation when two from section A and one from section B are glowing, will be [NEET 2019]$ (1) $9 : 4$ (2) $1 : 2$ (3) $2 : 1$ (4) $4 : 9$ 622. $If the resistance of each edge of a cube shaped wire frame as shown in figure below is R, then the resistance between points 1 and 7 is$ (1) $\frac{5 R}{6}$ (2) $\frac{R}{6}$ (3) $5R$ (4) $\frac{6}{5} R$ 623. $Two cells are connected between points A and B as shown. Cell 1 has emf of 12 V and internal resistance of 3 Ω . Cell 2 has emf of 6V and internal resistance of 6 Ω . An external resistor R of 4 Ω is connected across A and B. The current flowing through R will be______A.$ 624. $Four resistances of 15Ω, 12Ω, 4Ω and 10Ω respectively in cyclic order to form Wheatstone's network. The resistance that is to be connected in parallel with the resistance of 10Ω to balance the network is______Ω .$ 625. $A 16Ω wire is bend to form a square loop. A 9V supply having internal resistance of 1Ω is connected across one of its sides. The potential drop across the diagonals of the square loop is \times 1 0^{- 1} V$ 626. $An electric bulb rated as 200W at 100V is used in a circuit having 200V supply. The resistance 'R' that must be put in series with the bulb so that the bulb delivers the same power is Ω .$ 627. $In the given figure switches S1 and S2 are in open condition. The resistance across ab when the switches S1 and S2 are closed is _____Ω$ 628. $Two identical cells each of emf 1.5 V are connected in series across a 10 Ω resistance. An ideal voltmeter connected across 10 Ω resistance reads 1.5V. The internal resistance of each cell is_____Ω .$ 629. $All resistances in figure are 1 Ω each. The value of current T is \frac{a}{5} A. The value of a is______$ 630. $Two wires of same length and thickness having specific resistances 6Ω cm and 3Ω cm respectively are connected in parallel. The effective resistivity is ρΩ cm . The value of ρ to the nearest integer, is .$