Moving Charges and Magnetism-Quiz-12

MOVING CHARGES AND MAGNETISM - 12

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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. A particle of charge per unit mass α is released from origin with velocity v =v_0 i ̂ in a magnetic field B =-B_0 k ̂ for x≤√3/2 v_0/(B_0 α) And B =0 for x>√3/2 v_0/(B_0 α) The x-co-ordinate of the particle at time t(>π/(3B_0 α)) would be

•  √3/2 v_0/(B_0 α)+√3/2 v_0 (t-π/(B_0 α))
•  √3/2 v_0/(B_0 α)+v_0 (t-π/(3B_0 α))
•  √3/2 v_0/(B_0 α)+v_0/2 (t-π/(3B_0 α))
•  √3/2 v_0/(B_0 α)+(v_0 t)/2

Solution

Q2. Four very long, current carrying wires in the same plane intersect to form a square 40.0 cm on each side, as shown in figure. Find the magnitude and direction of the current I so that the magnetic field at the centre of the square is zero 

•  4.0 A toward the bottom of the page
•  2.0 A toward the bottom of the page
•  2.5 A toward the bottom of the page
•  3.6 A toward the top of the page

Solution

Q3. In Fig., there is a uniform conducting structure in which each small square has side a. The structure is kept in a uniform magnetic filed B. Then the magnetic force on the structure will be

•  2√2 iBa
•  √2 iBa
•  2 iBa
•   iBa

Solution

Q4. A particle is moving with velocity v =i +3j and it produces an electric filed at a point given byE =2k ̂. It will produce magnetic field at that point equal to (all quantities are in S.I. units)

•  (6i ̂-2j ̂ ) μ_0 ε_0
•  (6i ̂+2j ̂ ) μ_0 ε_0
•  zero
•  Cannot be determined from the given data

Solution

Q5. A charged particle of specific charge (charge/ mass) α is released from origin at time t=0 with velocity v =v_0 (i ̂+j ̂) in uniform magnetic fieldB =B_0 i ̂. Coordinates of the particle at time t=π(B_0 α) are

•  (v_0/(2B_0 α),(√2 v_0)/(αB_0 ),(-v_0)/(B_0 α))
•  ((-v_0)/(2B_0 α),0,0)
•  (0,(2v_0)/(B_0 α),(-v_0π)/(2B_0 α))
•  ((v_0 π)/(B_0 α),0,(-2v_0)/(B_0 α))

Solution

Q6. In a moving coil galvanometer, we use a radial magnetic feild so that the galvanometer scale is

•  logarithmic
•  Exponential
•  linear
•  none

Q7. A positively charged disk is rotated clockwise as shown in figure. The direction of the magnetic field at point A in the plane of the disk is

•  x into the page
  
  
•  3/4 →
  
  
•  ←3/4
  
  
•  . out of the page