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3), , 4), , 5), , 6), , 7), , 8), , 9), , VISION SCHOOL OF SCIENCE, NADIAD, , , , GENERAL TEST, Paper —3 Date : 1201/2022, Chapter Total Marks :, . PHYSICS, A flow of 10° electrons per second in a conducting wire constitutes a current of, (a) 1.6 «10? A (b) 1.6 x 10° A (c) 16x 10°°A (d) 1.6« 10° A, , A wire 50 cm long and I mm2 in cross-section carries a current of 4 A when connected to a 2 V battery. The, resistivity of the wire is..., , (a)4x 10% Om (b) 1x 10% Om (c)2x 107 Om (d)5x 107 Om, , The masses of the wires of copper is in the ratio of | : 3 : 5 and their lengths are in the ratio of 5 : 3: 1. The ratio, of their clectrical resistance is, , @123:5 (b)5:3:1 fo) & 252/125 (d) 125: 15:1, , A charged particle having drift velocity of 7.5 x 10“ ms~ in an electric field of 3 x 10°" V nr", has a mobility in, , m V1 $1 of..., , , , , , , , , , (a) 2.25 x 10'5 (b) 2.5 x 10° (c) 2.5 x 10° (d) 2.25 x 10°, , The color code of a resistance is given below The valucs of, , resistance and tolerance, respectively, are.... — | =, (a) 470 kW, 5% (b) 47 KW, 10%, , (c) 4.7 KW, 5% (d) 470 W, 5% Yellow Violet Brown Gold, , A carbon resistor of (47 + 4.7) kQ is to be marked with rings of different colours for its identification. The colour, code sequence will be, , (a) Violet — Yellow — Orange — Silver (b) Yellow — Violet — Orange — Silver, , (c) Yellow — Green — Violet — Gold (d) Green — Orange — Violet — Gold, , If voltage across a bulb rated 220 volt-100 watt drops by 2.5% of its rated value, the percentage of the rated value, by which the power would decrease is, , (a) 20% (b) 2.5% (c) 5% (d) 10%, Two bulbs are of (40 W, 200 ¥V), and (100 W, 200 V), Then correct relation for their resistances is, (a) Ran < Rico (b) Rao > Rim {c) Ray = Ram (d) no relation can be predicted, , A4uF capacitor is charged to 400 V. If its plates are joined through a resistance of 2 © W, then heat produced in, the resistance is, , (a) 0.64) (b) 1.28 (c) 0.163 (d) 0.32

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10) The total power dissipated in watt in the circuit shown here is..., (a) 40, (b) 54, (co) 4, (d) 16, 11) The current in the given circuit is... ., (a49A, (b) 6.8 A, (c)83A, (204, 12) The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Qis......, (a) 0.8.Q (b) 1.02 {c) 0.2Q 052, 13) In the network shown in the figure, cach of the resistance is equal to 2 Q. The, , , , , , , , , , , , R-=6Q2, , resistance between the points A and B is......., (a)3Q, (b) 40, (c) 1Q, (d) 20, , , , 14) A potentiometer circuit has heen set up for finding the internal resistance of a given cell. The main battery, used, across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire, itself is 4 m long. When the resistance R, connected across the given cell, has values of (i) infinity (ii) 9.5 Q the, balancing lengths on the potentiometer wire are found to be 3 m and 2.85 m, respectively. The value of internal, resistance of the cell is..., , (a) 0.25 (b) 0.95 2 {c) 0.5.2 (d) 0,75., , 15) A metallic rod of mass per unit length 0.5 kg m ‘ is lying horizontally on a smooth inclined plane which makes an, angle of 30° with the horizontal. The rod is not allowed to slide down by flowing a current through it when a, magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing in the rod to keep it, Stationary is... ..., , (a) 714A (b) 5.98 A {c) 14.76 A (d) 132A, , 16) A long straight wire carries a certain current and produces a magnetic field 2 x 10“ Wb m7” at a perpendicular, distance of 5 cm from the wire, An electron situated at 5 cm from the wire moves with a velocity 10’ m/s towards, the wire along perpendicular to it. The force experienced by the electron will be.(charge on electron 1.6 x 10°'* C), (a)3.2N (b) 3.2 x 10°°N (c) 1.6 10'°N (d) zero

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17) Under the influence of a uniform magnetic field, a charged particle moves with a constant speed v in a circle of, radius R. The time period of rotation of the particle, (a) depends on R and not on v (bh) is independent of hoth v and R, (c) depends on both v and R (d) depends on v and not on R., , 18) A charge having c/m equal to 10° C/kg and with velocity 3 x 10° ms enters into a uniform magnetic field B = 0.3, tesla at an angle 30° with direction of field. The radius of curvature will be, (a) 0.01 cm (b) 0.S cm (c) lem (d)2cm, , 19) Magnetic field due to 0.1 A current flowing through a circular coil of radius ().1 m and 1(MX) turns at the centre of, the coil is, (a) 6.28 x 10 T (b) 4.31 x 107 T ()2« 10° T (d) 9.81 x 104 T, , 20) A rectangular coil of length 0.12 m and width 0.1 m having 50 turns of wire is suspended vertically in a uniform, magnetic field of strength 0.2 Weber’m2. The coil carries a current of 2 A. If the plane of the coil is inclined at an, angle of 30° with the direction of the field, the torque required to keep the coil in stable equilibrium will be, (a) 0.24Nm (b)O.12Nm {c) 0.15 Nm (d) 0.20Nm, , 21) If number of turns, area and current through a coil is given by n, A and i respectively then its magnetic moment, will be..., (a) niA (b) iA (c) nia? @s, , 22) A circular loop of area 0.01 m? carrying a current of 10 A, is held perpendicular to a magnetic field of intensity, 0.1 T. The torque acting on the loop is, (a) 0.001 N m (b) 0.8 Nm {c) zero (d) 0.01 Nm, , 23) To convert a galvanometer into a ammeter, one needs to connect a, , (a) low resistance in parallel {b) high resistance in parallel, (c) low resistance in series (d) high resistance in series, 24) In an A.C. circuit, J, and Jp are related as... ..., (a) Ipms = My (b) rms = V2Iq © Inms = loft (d) Iems = Io/V2, , 25) In an ac circuit an alternating voltage 200 V2 sin100 t volts is connected to a capacitor of capacity | wF. The rms., value of the current in the circuit is, , (a) 10 mA (b) 100 mA (c) 200 mA (d) 20 mA, 26) A capacitor of capacity C has reactance X. If capacitance and frequency become double then reactance will be..., (a) 4X (b) X/2 (c) X/4 (d) 2X, , 27) An ac voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both, equal to 3 Q, the phase difference between the applied voltage and the current in the circuit is..., (a) 1/6 (b) 1/4 (c) 2/2 (d) zero

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28) In an a.c. circuit the e.m.f. (e) and the current (i) at any instant are given respectively by e = E,sinwt, i =, Iysin(wt-f). The average power in the circuit over one cycle of a.c, is..., , (a) = cosp (b) Bala () (@) sing, , 29) A coil of inductive reactance 31 © has a resistance of 8 Q. It is placed in series with a condenser of capacitative, reactance 25 ©. The combination is connected to an a.c. source of 110 V. The power factor of the circuit is...., (a) 0.33 (b) 0.56 (c) 0.64 (d) 0.80, , 30) The primary of a transformer when connected to a de battery of 10 volt draws a current of 1 mA. The number of, turns of the primary and secondary windings are 50 and 100 respectively. The voltage in the secondary and the, current drawn by the circuit in the secondary are respectively, (a) 20 V and 2.0 mA {b) 10 V and 0.5 mA, (c) Zero volt and therefore no current {d) 20 V and 0.5 mA, , 31) A 800 tur coil of effective area 0.05 m* is kept perpendicular to a magnetic field 5 x 10° T. When the plane of, the coil is rotated by 90° around any of its coplanar axis in 0,1 s, the emf induced in the coil will be, (a) 0.02 V (b)2V {c) 0.2 V (d)2x 10° V, , 32) A coil of resistance 400 Q is placed in a magnetic field. If the magnetic flux $(Qb) linked with the coil varies with, time t (sec) as @ = 500 + 4. The current in the coil at t = 2 see is, (@O5SA (b) OTA {c)2A (1A, , 33) As a result of change in the magnetic flux linked to the closed loop as shown in the figure, an, c.m.f, V volt is induced in the loop, The work done (joulk) in taking a charge Q coulomb once, along the loop is..., (a) QV, (b) 2QV, (c) QV/2, (d) zero, , 34) A rectangular coil of 20 turns and area of cross-section 25 sq. cm has a resistance of 100 Q. If a magnetic field, which is perpendicular to the plane of coil changes at a rate of 1000 tesla per second, the current in the coil is, (ajlA (b) SOA ()O5A W)5A, , 35) A magnetic field of 2 x 107 T acts at right angles to a coil of area 100 cm’, with 50 turns. The average e.m.f., induced in the coil is 0.1 V, when it is removed from the field in ¢ sec. The value of 1 is......., (a) 10s (b) 0.1 s (c) 0.01 s (dj ls, , 36) Faraday’s laws are consequence of conservation of, (a) energy (b) energy and magnetic field, (c) charge (d) magnetic field

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37) A cycle wheel of radius 0.5 m is rotated with constant angular velocity of 10 rad/s in a region of magnetic field of, 0.1 T which is perpendicular to the plane of the wheel. The EMF generated between its centre and the rim is, (a) 0.25 V (b) 0.125 V {c) 0.5 V (d) zero, , 38) The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA., This inductor is of inductance, (a) 0.138 H (b) 138.88 H (c) 1.389 H (d) 13.89 H, , 39) Two coils have a mutual inductance 0.005 H. The current changes in the first coil according to equation | =, Ip Sinwt, where Ip = 10 A and @ = 1002 rad/sec. The maximum value of ¢.m.f. in the second coil is, (a) (b) Sa (c)2 (d4a, , 40) What is the self-inductance of a coil which produces 5 V when the current changes from 3 ampere to 2 ampere in, , one millisecond?, , (a) 5000 henry (b) 5 milli-henry {c) 50 henry (d) 5 henry, 41) A 100 millihenry coil carries a current of 1A. Energy stored in its magnetic field is... ..., (a) O5I (by 1d (c) 0.053 (d) 0.15, , 42) On decreasing the angular frequency of A.C. source used in L-C-R series circuit, the capacitive reactance ... .., and inductive reactance ., , (A) Increases, Decreases (B) Increases, Increases (C) Decreases, Increases (D) Decreases, Decreases, 43) What is the r.m.s, value of the current for A.C. current T= 100cos(200t + 45°) A., (A) 50V2A (B) 100A (C) 100V2 A (D) Zero, 44) If in an A.C. L-C series circuit X1.> Xe, Hence current ....., (A) lags behind the voltage bys in phase (B) leads the voltage by : in phase, (C)leads the voltage by in phase (D) lags behind the voltage by 7 in phase, 45) In R-C circuit when charge on the plates of the capacitor is increasing, the cnergy obtained from the source is, stored in ......., (A) electric field (B) magnetic field, (C) gravitational field (D) both magnetic field and gravitational field, , 46) A charge q is placed at the centre of the line joining two equal charges Q. The system of the three charges will he, in equilibrium if q is cqual to, , (A) -Q/4 (B) Qi4 (C)-Q/2 (D) Q2, 47) An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field, , E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from, rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of, the proton is, , (A) smaller (B) 5 times greater (C) 10 times greater (D) equal