QUESTION #3 Magnetic Force on a Charge

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): An electron in a certain region of uniform magnetic field is moving with constant velocity in a straight line path. Reason (R): The magnetic field in that region is along the direction of velocity of the electron. In the light of the above statements, choose the correct answer from the options given below:

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QUESTION #5 Ampere's Circuital Law

A long straight wire of a circular cross-section with radius 'a' carries a steady current I. The current I is uniformly distributed across this cross-section. The plot of magnitude of magnetic field B with distance r from the centre of the wire is given by:

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QUESTION #11 Ampere's Circuital Law

N equally spaced charges each of value q, are placed on a circle of radius R. The circle rotates about its axis with an angular velocity omega$\omega$ as shown in the figure {{IMG1}}. A bigger Amperian loop B encloses the whole circle where as a smaller Amperian loop A encloses a small segment. The difference between enclosed currents, I_A - I_B$I_{A} - I_{B}$, for the given Amperian loops is

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QUESTION #21 Solenoid

A tightly wound long solenoid carries a current of 1.5 A. An electron is executing uniform circular motion inside the solenoid with a time period of 75ns. The number of turns per metre in the solenoid is ____. {{IMG1}} [Take mass of electron m_e = 9 times 10^-31$m_e = 9 \times 10^{-31}$ kg, charge of electron |q_e| = 1.6 times 10^-19$|q_e| = 1.6 \times 10^{-19}$ C, mu_0 = 4pi times 10^-7 fracNA^2, 1 text ns = 10^-9 text s$\mu_0 = 4\pi \times 10^{-7} \frac{N}{A^2}, 1 \text{ ns} = 10^{-9} \text{ s}$]

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