Question: Mutually inductance between two magnetically-coupled coils depends on____________?

• 1. permeability of the core
• 2. the number of their turns
• 3. cross-sectional area of their common core
• 4. all of the above

Question: The law that the induced e.m.f. and current always oppose the cause producing them is due to____________?

• 1. Faraday
• 2. Lenz
• 3. Newton
• 4. Coulomb

Question: If current in a conductor increases then according to Lenz’s law self-induced voltage will____________?

• 1. aid the increasing current
• 2. tend to decrease the amount of cur-rent
• 3. produce current opposite to the in-creasing current
• 4. aid the applied voltage

Question: Air-core coils are practically free from______________?

• 1. hysteresis losses
• 2. eddy current losses
• 3. both (A) and (B)
• 4. none of the above

Question: The property of coil by which a counter e.m.f. is induced in it when the current through the coil changes is known as__________?

• 1. self-inductance
• 2. mutual inductance
• 3. series aiding inductance
• 4. capacitance

Question: The direction of induced e.m.f. can be found by_____________?

• 1. Laplace’s law
• 2. Lenz’s law
• 3. Fleming’s right hand rule
• 4. Kirchhoff s voltage law

Question: An open coil has_____________?

• 1. zero resistance and inductance
• 2. infinite resistance and zero inductance
• 3. infinite resistance and normal inductance
• 4. zero resistance and high inductance

Question: The inductance of a coil will increase under all the following conditions except______________?

• 1. when more length for the same number of turns is provided
• 2. when the number of turns of the coil increase
• 3. when more area for each turn is provided
• 4. when permeability of the core increases

Question: As per Faraday’s laws of electromagnetic induction, an e.m.f. is induced in a conductor whenever it_______________?

• 1. lies perpendicular to the magnetic flux
• 2. lies in a magnetic field
• 3. cuts magnetic flux
• 4. moves parallel to the direction of the magnetic field

Question: In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will_____________?

• 1. increase
• 2. decrease
• 3. remain the same
• 4. initially increase and then decrease