85. V B is based on

A. Gauss's law

B. Ampere's law

C. Faraday's law

D. Ohm's law

86. The Biot-Savart's law is a general modifi-cation of

A. Coulomb law

B. Ampere's law

C. Faraday's law

D. Ohm's law

87. The direction of mechanical force experienced on a current carrying conductor placed in a magnetic field is determined by

A. Fleming's left hand rule

B. Fleming's right hand rule

C. Helix rule

D. Cork screw rule

88. If a current carrying conductor is placed in a magnetic field, the mechanical force experienced on the conductor is determined by

A. simple product

B. dot product

C. cross product

D. any of these

89. The force experienced by a current carrying conductor lying parallel to a magnetic field is

A. zero

B. B I /

C. B I / sin 0

D. B I /cos 0

90. An in finitely long conductor carrying a current is embedded in a semi-infinite medium of permeability pp as shown in the given figure. For itti > ja2, the conductor will experience

A. no force

B. a force that moves it away from the interface

C. a force towards the interface

D. a force parallel to the interface.

91. A straight conductor of length / moving with a velocity v in the presence of a magnetic field of flux density B directed at an angle 0 with the direction of v experiences a force. Which of the following statement(s) is/are true for the magnitude of the force? 1. It is independent of 0.2. It is proportional to /2. 3. It is proportional to B. 4. It is independent of v. Select the correct answer from the codes given below :Codes :

A. 1, 2 and 3

B. 4 alone

C. 3 alone

D. 2 and 4

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