Q.1
The current through a 120 mH coil is changing at a rate of 150 mA/s. The voltage induced across the coil is
Q.2
A switch, a 220 Ω resistor, and a 60 mH inductor are in series across a 20 V battery. What is the current through the inductor two time constants after the switch is closed?
Q.3
Two 10 H inductors are in parallel and the parallel combination is in series with a third 10 H inductor. What is the approximate total reactance when a voltage with a frequency of 7 kHz is applied across the circuit terminals?
Q.4
A 5 mH, a 4.3 mH, and a 0.6 mH inductor are connected in parallel. The total inductance is
Q.5
Three 15 mH inductors are in series. The total inductance is
Q.6
An inductance of 0.08 µH is larger than
Q.7
An inductance of 0.43 mH is smaller than
Q.8
The voltage across a coil when di/dt = 20 mA/µs and L = 8 µH is
Q.9
What is the symbol for Inductance?
  • I
  • Z
  • XL
  • L
Q.10
Lamination of transformer core is made of
  • Cast Iron
  • Silicon Steel
  • Aluminium
  • Cast Steel
Q.11
If supply frequency of a transformer increases, the secondary output voltage of the transformer
  • Increase
  • Decrease
  • Remain the same
  • Any of the above
Q.12
Inductor stores energy in the form of
  • Electric field
  • Electromagnetic field
  • Magnetic field
  • None of the above
Q.13
To demonstrate static electricity, a teacher takes an inflated balloon and rubs it against his hair. The rubber balloon picks up electrons from his hair, which makes his hair have
  • a net negative charge
  • a magnetic force
  • a net positive charge
Q.14
------------------------ is created out of two metal plates and an insulating material called a dielectric.
  • An inductor
  • A capacitor
  • A fixed resistor
  • A variable resistor
Q.15
The production of a voltage across an inductor as a result of its own expanding or contracting magnetic field is called ____.
  • Flux density
  • Self-inductance
  • Counter emf
  • Faraday's second law
Q.16
Neutrons have a __________ charge.
  • Negative
  • Positive
  • Neutral
Q.17
Why do socks stick together when they come out of the dryer?
  • One has a negative charge and the other has a positive charge
  • Both have negative charges
  • Both have positive charges
Q.18
The closer the charges, the ___________ the force between them
  • closer
  • further
  • stronger
  • weaker
Q.19
If a substance has a higher number of electrons than protons on its surface, what type of charge does it have?
  • A positive charge.
  • A negative charge.
  • A neutral charge
  • No charge at all
Q.20
What types of charges repel?
  • Positive and Positive
  • Positive and Neutral
  • Negative and Neutral
  • Neutral and Neutral
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