Q.1

For a pure capacitor:

  • ac current and voltage are exactly in phase
  • ac current leads the voltage by 90 degree
  • ac current is converted to dc voltage
  • ac current lags the voltage by 90 degree
  • None of the above
Q.2

What is the phase shift between total current and voltage in the circuit of aohm resistor connected in parallel with a capacitor that has a reactance ofohm

  • 180 degree
  • 30 degree
  • 45 degree
  • 75 degree
  • None of the above
Q.3

In an intrinsic semiconductor, the number of free electrons

  • Equals the number of holes
  • Is less than the number of holes
  • Is greater than the number of holes
  • Impossible to say
  • None of the above
Q.4

The component that forms the electrical connection between the rotating coil of wire in a motor and the external source of electrical energy is called the:

  • rotor
  • armature
  • battery
  • commutator
  • None of the above
Q.5

Molecule is

  • The smallest particle of a substance that retains the properties of that substance
  • A atom that has a shortage of electrons in its outer orbit
  • A atom that has an excessive number of electrons in its outer orbit
  • A atom that flows whenever there is an imbalance of electrical charges between two points
  • None of the above
Q.6

A device that converts mechanical into electrical energy is?

  • solar cell
  • thermocouple
  • chemical cell
  • generator
  • None of the above
Q.7

In a pure inductor:

  • ac current leads the voltage by 90 degree
  • ac current and voltage are exactly in phase
  • ac current lags the voltage by 90 degree
  • ac current is converted to dc voltage
  • None of the above
Q.8

What form of energy is used for creating static electricity?

  • Solar energy
  • Mechanical energy
  • Chemical energy
  • Light energy
  • None of the above
Q.9

Which one of the following kinds of materials has the lowest permeability?

  • A diamagnetic material
  • A paramagnetic material
  • A feiTomagnetic material
  • All of the above
  • None of the above
Q.10

Waveforms are graphs that show:

  • frequency on the vertical axis and amplitude on the horizontal axis
  • amplitude on the vertical axis and frequency on the horizontal axis
  • amplitude on the vertical axis and the passage of time on the horizontal axis
  • the passage of time on the vertical axis and amplitude on the horizontal axis
  • None of the above
Q.11

Suppose the zener diode has a breakdown voltage ofV and zener resistance of 8.5 W, what is the additional voltage when the current ismA?

  • 0.17 V
  • 10.17 V
  • 20 V
  • 18.8 V
  • None of the above
Q.12

The total impedance of a parallel RLC circuit:

  • always increases as the applied frequency increases
  • is equal to the sum of the values of resistance, inductive reactance and capacitive reactance
  • always decreases as the applied frequency increases
  • is maximum at the resonant frequency
  • None of the above
Q.13

When the collector current increases, what does the current gain do?

  • decreases
  • stays the same
  • increases
  • any of the above
  • None of the above
Q.14

A transistor has a current gain ofand a base current ofµA. What is the collector current?

  • 3.75 mA
  • 3.2 mA
  • 0.05 mA
  • 13 mA
  • None of the above
Q.15

The rise time of a pulse waveform is the time required for the voltage to rise:

  • from zero to its rms value
  • from zero to its peak value
  • from 10% of the peak value to 70.7% of the peak value
  • from 10% of the peak value to 90% of the peak value
  • None of the above
Q.16

Which one of the following statements applies to common auto batteries?

  • Auto batteries are primary wet-cell batteries
  • Auto batteries are secondary wet-cell batteries
  • Auto batteries are secondary dry-cell batteries
  • Auto batteries are primary dry-cell batteries
  • None of the above
Q.17

A transistor has how many doped regions?

  • 1
  • 2
  • 3
  • 4
  • None of the above
Q.18

Which one of the following equations most directly determines the power dissipation of a resistance when you know the power dissipation of a resistance when you know the voltage drop and current?

  • P = IE
  • P = E2/R
  • P = I2R
  • I = P/E
  • None of the above
Q.19

If N1/N2 =and the primary voltage isV, what is the secondary voltage?

  • 0 V
  • 36 V
  • 40 V
  • 60 V
  • None of the above
Q.20

The voltage across a 1Nis 0.when the current is 1A. What is the power dissipation of the diode for these values?

  • 0.93 W
  • 0.93 V
  • 1 A
  • 9.3 W
  • None of the above
Q.21

A loadstone is:

  • a natural magnet
  • a temporary magnet
  • an artificial magnet
  • a paramagnetic alloy
  • None of the above
Q.22

Which one of the following statements is true for voltage in a parallel circuit?

  • The total voltage in a parallel circuit is equal to the average value of the individual voltages
  • The total voltage in a parallel circuit is always less than the value of the smallest voltage
  • The total voltage is equal to the sum of the voltages across the individual branches in a parallel circuit
  • The total voltage of a parallel circuit is the same as the voltages across each branch
  • None of the above
Q.23

A device that converts light energy to electrical energy is called a:

  • thermocouple
  • solar cell
  • photodiode
  • photo transistor
  • None of the above
Q.24

How much current flows through a 60-W light bulb that is operating atV?

  • 0.5A
  • 180 A
  • 2 A
  • 7200 A
  • None of the above
Q.25

Which one of the following phrases most accurately describes a purely capacitive circuit?

  • Resistances provide the only opposition to current flow
  • Capacitive reactance provides the only opposition to current flow
  • The ac voltage leads the current by 90 degree
  • Combinations of resistance and capacitive reactance provide any opposition to current flow
  • None of the above
Q.26

The dielectric constant of a material is a measure of:

  • the amount of voltage it can withstand before breaking down
  • how well the material concentrates electrostatic lines of force
  • the amount of opposition to the current flow
  • how well the material concentrates magnetic lines of force
  • None of the above
Q.27

The saturation point is approximately the same as

  • cutoff point
  • lower end of the load line
  • upper end of the load line
  • infinity
  • None of the above
Q.28

What is the inductive reactance of a 2-H coil operating atHz?

  • 754 Ohm
  • 30 Ohm
  • 60 Ohm
  • 120 Ohm
  • None of the above
Q.29

When operating above its resonant frequency, a series RLC circuit has the characteristics of a:

  • series RL circuit
  • series RC circuit
  • series RLC circuit operated below its resonant frequency
  • purely resistive circuit
  • None of the above
Q.30

What is the primary difference between primary and secondary cell batteries?

  • Primary-cell batteries can be recharged and used many times, whereas secondary-cell batteries cannot be properly recharged
  • Secondary-cell batteries can be recharged and used many times, whereas primary-cell batteries cannot be properly recharged
  • Primary-cell batteries use chemical cells, whereas secondary-cell batteries use an alternative energy source, such as thermal or magnetic energy, to supplement their outputs
  • Primary-cell batteries must be recharged at a much slower rate that secondary-cell batteries
  • None of the above
0 h : 0 m : 1 s