Assertion: Acceleration of charged particle in non-uniform electric field does not depend on velocity of charged particle.
Reason: Charge is an invariant quantity. That is amount of charge on particle does not depend on frame of reference.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: Magnetic field is useful in producing parallel beam of charged particle.
Reason: Magnetic field inhibits the motion of
charged particle moving across it.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
What is the magnetic field on the axis of a coil of radius r carrying current I at a distance R from the origin?
A.
Consider a circular coil of radius r, carrying a current I. Consider a point P, which is at a distance X from the centre of the coil. We can consider that the loop is made up of a large number of short elements, generating small magnetic fields. So the total field at P will be the sum of the contributions from all these elements. At the centre of the coil the field will be uniform. As the location of the point increases from the centre of the coil, the field decreases.
By Biot-Savart's law, the field dB due to a small element 'dl' of the circle, centred at A is given by
dB =
This can be resolved into two components, one along the axis OP, ad other PS, which is perpendicular to OP. Ps get cancelled with PS'. So the magnetic field at a distance x away from the axis of circular coil of radius r is given by
Bx =
Assertion: When a magnetic dipole is placed in a non uniform magnetic field, only a torque acts on the dipole.
Reason: Force would act on dipole if magnetic field is uniform.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false.
If both assertion and reason are false.
Two parallel long wires A and B carry currents i1 and i2 ( < i2 ). When i1 and i2 are in the same direction, the magnetic field at a point mid way between the wires is 10 µT. If i2 is reverse the field becomes 30 µT. The ratio i1 / i2
1
2
3
4
Two conducting circular loops of radii R1 and R2 are placed in the same plane with their centres coinciding. If R1 > R2, the mutual inductance M between them will be directly proportional to
A long straight wire carries 10 A d.c. current an electron travels perpendicular to the plane of this wire at a distance 0.1 m with velocity 5.0 x 106 ms-1. Force acting on the electron due to current in wire is
zero N
0·6 × 10-17 N
2.4 × 10-17 N
2.2 × 10-17 N
Assertion: A charged particle free to move in an electric field always moves along an electric field line.
Reason: The electric field lines diverge from a negative charge and converge at a positive charge.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion: If an electron and proton possessing same kinetic energy enter an electric field in a perpendicular direction, the path of the electron is more curved than that of the proton.
Reason: Electron forms a larger curve due to its small mass.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false.
If both assertion and reason are false.