Electrical Engineering (EE)

In a transmission line terminated by characteristic impedance, Z0
  • a)
    the incident current is zero for only applied voltage.
  • b)
    there are large number of maximum and minimum on the line.
  • c)
    the reflection is maximum due to termination.
  • d)
    there is no reflection of the incident wave.
Correct answer is option 'D'. Can you explain this answer?

KIRAN DEVI answered  •  42 minutes ago
When a transmission line is terminated by an impedance Z, then reflection coefficient are:

Here, Z0 = Characteristic impedance of transmission line.
Since Z = Z0 therefore reflection co-efficient of voltage (pv) and current (pI) both will be zero, i.e there will be no reflection of incident wave.

For a TEM wave to propagate in a medium, the medium has to be
  • a)
    Air
  • b)
    Insulator
  • c)
    Dispersive
  • d)
    Non dispersive
Correct answer is option 'D'. Can you explain this answer?

REENA VERMA answered  •  42 minutes ago
Answer: d
Explanation: The medium in which the TEM waves propagate has to be non- dispersive. This implies the phase velocity and the characteristic impedance has to be constant over a wide band.

The forward resistance for a PIN diode is given by ________
  • a)
     RF = W/σP
  • b)
    RF = W/σN
  • c)
    RF = WσP
  • d)
     RF = WσN
Correct answer is option 'B'. Can you explain this answer?

Meghna Kataria answered  •  11 hours ago
Forward resistance for a PIN diode depends on the width, current density and positive carrier concentration of the diode. No diode is perfectly ideal. In practise, a diode offers a small resistance in forward bias which is called as forward resistance.

What is the other representation of the given PNP transistor connected in common emitter configuration?
  • a)
  • b)
  • c)
  • d)
Correct answer is option 'D'. Can you explain this answer?

Esakshi answered  •  11 hours ago
The emitter junction is forward biased with the help of battery VEE by which, negative of the battery is connected to the emitter while positive is connected to base. RE is the emitter resistance. The collector junction is reversed biased.

Assertion (A): For high power applications, inverters are used instead of transistors.
Reason (R): For high power applications, inverter is operated in active region.
  • a)
    Both A and R are true and R is the correct explanation of A.
  • b)
    Both A and R are true but R is not the correct explanation of A.
  • c)
    A is true but R is false.
  • d)
    A is false but R is true.
Correct answer is option 'C'. Can you explain this answer?

MANJEET KAUR answered  •  11 hours ago
In low-power electronic circuits oscillators are used for converting dc power into ac power. These oscillator use transistors for converting dc voltage into sinusoidal ac voltage. Since transistor is used in active region, therefore there is substantial loss of power which decreases efficiency. In high power applications inverters are used instead of transistors and the inverters operate in saturation region or cut-off region. Thus, assertion is true but reason is false.

Fetching relevant content for you