Moving Charges and Magnetism-Quiz-9

MOVING CHARGES AND MAGNETISM-9

Dear Readers,

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 particle Y and Z emitted but a radioactive source at P made tracks in chamber as illustrated in the Figure. A magnetic field acts downward into the paper. Careful measurement showed that both tracks were circular, the radius of Y track being half that of the Z track. Which one of the following statement is certainly true?

•   Both particles Y and Z carried a positive charge
•  The mass of particle Z was one-half that of particle Y
•  The mass of particle Z was twice that of particle Y
•  The charge of particle Z was twice that of particle Y

Solution

Q2.A coaxial cable is made up of two conductors. The inner conductor is solid and is of radius R_1 and the outer conductor is hollow of inner radius R_2 and outer radius R_3. The space between the conductors is filled with air. The inner and outer conductors is filled with air. The inner and outer conductors are carrying currents of equal magnitudes and in opposite directions. Then, the variation of magnetic filed with distance from the axis id best plotted as

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Solution

Q3.  An electron is ejected from the surface of a long, thick straight conductor carrying a current, initially in a direction perpendicular to the conductor . The electron will 

•  Ultimately return to the conductor 
•   Move in a circular path around the conductor
•   Gradually move away from the conductor along a spiral
•   Move in a helical path, with the conductor as the axis

Solution

Q4. There exist uniform magnetic and electric fields of magnitudes 1 T and 1 Vm^(-1) , respectively, along positive y-axis. A charged particle of mass 1 kg and charge 1 C is having velocity 1 ms^(-1) along x-axis and is at origin at t=0. Then, the coordinates of the particle at time π sec will be

•  (0, 1, 2)m
•  (0,-π2,-2)m
•  (2,π^2/2,2)m
•  (0,π^2/2,2)m

Solution

Q5.  A coil having N turns is wound tightly in the form of a spiral with inner and outer radii a and b, respectively. When a current I passes through the coil, the magnetic field at the centre is

 

•  (μ0 NI)/b
•  (2μ0 NI)/a
•  (μ0 NI)/(2(b-a)) In b/a
•  (μ0 I^N)/(2(b-a)) In b/a

Solution
 

Q6. A particle of positive charge q and mass m enters with velocity Vj ̂ at the origin in a magnetic field B(-k ̂) which is present in the whole space. The charge makes a perfectly inelastic collision with an identical particle (having same charge) at rest but free to move at its maximum positive y-coordinate. After collision, the combined charge will move on trajectory (where r=mV/qB)

•  y=mv/qB x
•  (x+r)^2+(y-r⁄2)^2=r^2/4
• (x+r)^2+(y-r/2)^2=r^2/8
•  (x-r)^2+(y+r/2)^2=r^2/4

Solution

Q7.A circular coil having mass m is kept above ground (x-z plane) at some height. The coil carries a current i in the direction shown in fig. In which direction a uniform magnetic field B vector be applied so that the magnetic force balances the weight of the coil?

•   Positive x direction
•   Negative x direction
•  Positive z direction
•   none of these

Solution

Q8.An electron is moving along positive x-axis. To get it moving on an anticlockwise circular path in x-y plane, a magnetic field is applied

•  Along positive y-axis
•  Along positive z-axis
•  Along negative y-axis
•  Along negative z-axis

Solution

Q9.For c=2a and a<b<c, the magnetic field at point P will be zero when

•  a=b
•  a=3/5 b
•  a=5/3 b
•  a=1/3 b

Solution

Q10. Two infinity long linear conductor are arranged perpendicular to each other and are in mutually perpendicular planes as shown in figure. If I1=2A along the y-axis, I2=3 A along –ve z-axis and AP=AB=1 cm, the value of magnetic filed strength B vector at P is

•  (3×10^(-5) T) j ̂+(-4×10^(-5) T)k ̂
•  (3×10^(-5) T) j ̂+(4×10^(-5) T)k ̂
•  (4×10^(-5) T) j ̂+(3×10^(-5) T)k ̂
• (-3×10^(-5) T) j ̂+(4×10^(-5) T)k ̂

Solution