11.The force of attraction or repulsion between two magnetic poles is inversely proportional to the square of the distance between them. This is known as
A. Newton’s first law
B. Faraday’s first law of electromagnetic induction
C. Coulomb’s first law
D. Coulomb’s second law
12. Whenever a conductor cuts magnetic flux, an emf is induced in it. This is known as
A. Coulomb’s law
B. Joule’s law
C. Faraday’s law
D. Ohm’s law
13. A law that states that the polarity of the induced voltage will oppose the change in magnetic flux causing the induction.
A. Joule’s law
B. Faraday’s law
C. Coulomb’s law
D. Lenz’ law
14. A law that states that the current in a thermionic diode varies directly with the three- halves power of anode voltage and inversely with the square of the distance between the electrodes, provided operating conditions are such that the current is limited only by the space charge.
A. Hall’s law
B. Joule’s law
C. Child’s law
D. Coulomb’s law
15. States that the ratio of the thermal conductivity is proportional to the absolute temperature for all metals.
A. Wien’s displacement law
B. Hartleys law
C. Hall’s law
D. Wiedemann Franz law
16. A law establishing the fact that the algebraic su of the rises and drops of the mmf around a closed loop of a magnetic circuit is equal to zero.
A. Kirchhoff’s circuital law
B. Maxwell’s circuital law
C. Ampere’s circuital law
D. Coulomb’s circuital law
17. The net electrical charge in an isolated system remains constant. This is known as
A. Law of conservation of charge
B. Coulomb’s first law
C. Coulomb’s second law
D. Law of conservation of energy
18. Lenz’s law is the consequence of the law of conservation of
A. Energy
B. Charge
C. Field lines
D. Momentum
19. Lenz’ law states that the direction of the induced emf and hence current
A. Is determined by the rate of current flux
B. Is found by the right hand rule
C. Is found by the left hand rule
D. Always opposes the cause producing it
20. If you hold the conductor with right hand so that the stretched thumb points in the direction of the current, then encircling fingers will give the direction of magnetic lines of force round the conductor. This is known as
A. Left hand cork screw rule
B. Right hand cork screw rule
C. Left hand rule
D. Right hand rule