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TEJAS ACADEMY OF SCIENCE, , Physics, , , , Time : 1.00 hr xil Marks : 20, , , , , , 1), , 2), , 3), , 4), , 5), , 6), , 8), , 9), , Electromagnetic Inductions |, , The self inductance of a coil having 100 turns is 10 mH. What is the magnetic flux linked with each turn, of the coil, if a current of 4 mA is passed through the coil ?, , A) 4 «1077 weber B) 2 «10-7 weber C)1 «10-7 weber D) 8 «107? weber, A coil of self inductance 80 mH carries a current of 2 A. What is the energy stored in the coll ?, , AOS B)16J C)0.16/ D)O4J, , i a current of 3 A flowing in the primary coil is reduced to zero in 0.01 s, the e.m.f. induced in the, secondary coil is 750 V. What is the mutual inductance between the two coils ?, , A)1.5H B) 2H C)2.5H D)3H, An inductor stores the energy in, , A) ils electric field B) its coil, , C) its magnetic field D) both in electric and magnetic fields, , If the current flowing In a coll Is reduced to half of Its original value, the relation between the new, energy ( Ep ) and the original energy ( E, ) stored in the coil will be, , 1, qe, , if a current of 3 A, flowing in the primary coil is reduced to zero in 10— s, the induced e.m.t. in the, secondary coil is 15000 V. The mutual inductance between the two coils is, , A) Ea = Es B) Ep = 2E; co Ee = 38 D) Ep =, , A)SH B) 10H C)0.5H D)25H, , A long solenoid has 500 turns. When a current of 2 Ais passed through it, the resulting magnetic flux, linked with each tum of the solenoid is 4 x 10~? Wb. What is the selfinductance of the solenoid ?, , A)2H B) 1.5H c)1H D)O5H, , Which one of the following is the unit of self inductance of a coil ?, , A) Vol i 1A~? B) Vol t-1A C) Volt sec A~' D) Vol t-1A~" sec, In a car spark coil, an e.m.f. of 4000 V is Induced in the secondary when the primary current changes, , from 4 A to 0A in 10 1. s. What is the mutual inductance between the primary and secondary windings, of the spark coil ?, , A)O.1H B)0.2H C)0.01H D)O.5H, , 10) Hf L is the inductance and R is the resistance, then the unit of is, , A) Ampere B) Volt C) Per sec D) Sec

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TEJAS ACADEMY OF SCIENCE 2, , , , 11) The coefficient of mutual inductance of two coils is 6 mH. If the current flowing in one coil is 2 ampere,, then the induced e.m.f. in the second coil will be, , A)2mvV B)3Vv C) Zero D)3mv, 12) In the following circuit, the bulb will become suddenly bright if, L, , —, A) Contact is made B) Wont become bright at all, C) Contact is made or broken D) Contact is broken, , 13) A 200 mH coil carries a current of 1 A. The energy stored in its magnetic field is, , AVOS JS B)1J Cord D) 0.05 J, , 14) In a coil, the current increases from 0 to 6A in 0.4 s. If an induced e.m.f. of 15 V is produced in the coil,, then the coefficient of self-induction of the coil will be, , A)OSH B) 0.75H Cc)1H D)1.5H, , 15) The current In the primary coll at time tis given by |. (St? 4) Ampere. If the e.m.f. Induced In the, secondary coil is given by c, = 32 = 10 * t volt, then the mutual inductance between the two coils is, , A) 1 millinenry B) 2mH Cc) 5 mH D) 10 mH, , 16) The self inductance L of a solenoid of length | and area of cross-section A, with a fixed number of, turns N increases as, , A) Land A increase B) | decreases and A increases, , C) L increases and A decreases D) both | and A decrease, 17) Two colls are placed close to each other. The mutual inductance of the pair of coils depends upon, , A) the rates at which currents are changing in the two coils, B) relative position and orientation of the two colls, C) the materials of the wires of the coils, , D) the currents in the two coils, , 18) Two colls P and S have a mutual inductance of 5 x10 * H, If the current in the primary Is I = 10 sin(, 100nt ), then the maximum value of the e.m.f. induced in S is, , A) 6.28 V B) 12.56 V C) 15.70 V D)3.14V, , 19) 3 pure inductors each of inductance 3H are connected as shown in the figure. The equivalent, inductance of the circuit between A and B is, , , , Rahul Chavan Sir 9130013007