Electromagnetic Induction - Quiz 4

Electromagnetic induction : 4

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JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts..

Q1. Two identical circular loops of metal wire are lying on a table without touching each other. Loop- A carries a current which increases with time. In response, the loop-B

•   Remains stationary
•   Is attached by the loop A
•  Is repelled by the loop A
•  Rotates about its CM with CM fixed

Solution
c

Q2.A closed circuit consists of a resistor R; inductor of inductance L and a source of e.m.f. E are connected in series. If the inductance of the coil is abruptly decreased to L/4 (by removing its magnetic core), the new current immediately after this moment is (before decreasing the inductance the circuit is in steady state)

•   Zero
•  E/R
•  4 E/R
•  E/4R

Solution
c

Q3.  In fig switch S is closed for a long time. At t=0, if it is opened, then

•  Total heat produced in resistor R after opening the switch is 1/2 Lℇ/R²
•  Total heat produced in resistor R₁ after opening the switch is 1/2 (Lℇ²)/R² (R₁/(R₁+R₂ ))
•  Heat produced in resistor R₁ after opening the switch is 1/2 (R₂ LE²)/((R₁+R₂ ) R² )
•  No heat will be produced in R₁

Solution
c

Q4.  In the circuit shown in fig, switch S is closed at time t=0. The charge that passes through the battery in one time constant is

•  (eR² E)/L
•  E(L/R)
•  EL/(eR² )
•  eL/ER

Solution
c

Q5.The radius of the circular conducting loop shown in figure isR. Magnetic field is decreasing at a constant rateα. Resistance per unit length of the loop is p

Then, the current in wire AB is (AB is one of the diameters)

•  Rα/2ρ from A to B
•  Rα/2ρ from B to A
•  Rα/ρ from A to B
•  0

Solution
 d

Q6. 6. An elasticized conducting band is around a spherical balloon figure. Its plane passes through the centre of the balloon. A uniform magnitude field of magnitude 0.04 T is directed perpendicular to the plane of the band. Air is let out of the balloon at 100 cm³/a at an instant when the radius of the balloon is 10 cm. The induced emf in the band is

•  15 μV
•  25 μV
•  10 μV
•  20 μV

Solution
d

Q7. Two identical cycle wheels (geometrically) have different number of spokes connected from centre to rim. One is having 20 spokes and the other having only 10 (the rim and the spokes are resistanceless). One resistance of value R is connected between centre and rim. The current in R will be

•  Double in the first wheel than in the second wheel
•  Four times in the first wheel than in the second wheel
•  Will be double in the second wheel than that of the first wheel
•  Will be equal in both these wheels

Solution
d

Q8. A rod lies across frictionless rails in a uniform magnetic field B ⃗ as shown in figure. The rod moves to the right with speedV. In order to make the induced emf in the circuit to be zero, the magnitude filed should

•   Not change
•  TIncreases linearly with time
•  Decreases linearly with time
•  Decrease nonlinearly with time

Solution
d

Q9. In an LC circuit shown in fig, C=1 F,L=4 H. At time t=0, charge in the capacitor is 4 C and it is decreasing at the rate of √5 Cs-1. Choose the correct statement

•  Maximum charge in the capacitor can be 6 C
•  Maximum charge in the capacitor can be 8 C
•  Charge in the capacitor will be maximum after time 3 sin^-1⁡〖(2/3)〗 s
•  None of these

Solution
a

Q10. The current passing through the battery immediately after key (K) is closed [it is given that initially all the capacitors are uncharged (given that R=6 Ω and C=4 μF)] is

•  1 A
•  5 A
•  3 A
•  2 A

Solution
a