Physics 2nd Test

For induced emf in a coil the basic requirement is that

• Flux should link the coil
• Change in flux should link the coil
• Coil should form a close loop
• Coil must have turns

The unit of “Henry “is used for

• Self-induction
• induced emf
• Mutual induction
• Self-inductance

When a potential difference of 4 volt is applied across resistance, 10J of energy is converted. Find charge flows

• 0.20C
• 0.25C
• 2.5C
• 10.0C

The magnitude of motional emf is

• ε = VBL
• ε = -VBL
• ε = V/BL
• ε = -L/VB

Faraday’s law of electromagnetic induction has been used in the construction of

• ammeter
• Electric generator
• Galvanometer
• All of these

The rate of change of magnetic flux is directly proportional to the induced emf is called

• Lenz law
• Faraday’s law
• Oersted’s law
• Ampere's law

A steady current is passing through a coil, magnitude of self-induced emf in it, will be

• zero
• maximum
• ε = L ΔI / Δt
• ε = - L ΔI / Δt

Principle of dynamically induced emf is used in

• choke
• transformer
• generator
• thermo couple

In Flehmming's left hand rule, thumb always indicates the direction of

• current flow
• induced emf
• magnetic field
• mechanical force

When a coil is rotating in magnetic field the induced current in it

• remain same
• Continously changing
• becomes zero
• becomes maximum