# Electrical length of an antenna is

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Electrical length of an antenna is Greater than physical length.

## Related questions

When a dipole antenna of 1/8 length has an equivalent total resistance of 1.5 Watt then the efficiency of the antenna is   (A) 0.89159% (B) 8.9159% (C) 89.159% (D) 891.59%

An SSB transmitter produces a peak-to-peak voltage of 200 V across a 100 Ω antenna load. What is the Peak Envelope Power? A) 49.98 W B) 79.98 W C) 99.96 W D) 199.93 W

For an earth station transmitter, with an antenna output power of 40dBW 10,000W, a back-off loss of 3dB, a total branching and feeder loss of 3dB, a total branching and feeder loss of 3dB and transmit antenna gain of 4dB, the effective isotropic radiated power (EIRP will be  a) 38dBW b) 40 dBW c 36 dBW d) 47 dBW

The directive gain of an antenna: (1) is less than or equal to 1 (2) is greater than or equal to 1 (3) lies between 0 and directivity of antenna (4) is greater than directivity of antenna

To increase gain of a parabolic reflector antenna by 6dBi, the correct statement is : ( Assuming efficiency 70%) a. Diameter is to be increased to 6 folds b. Diameter is to be increased to 4 folds c. Diameter is to be increased to 2 folds d. None of above

The gain of a parabolic dish antenna of 1 m diameter -and 80% efficiency at 9.5 GHz is: a. 39 dB b. 78 dB c. 40 dB d. 45 dB

If the antenna diameter in a radar system is increased by a factor of 4, the maximum range will be increased by a factor of  (a) 2 (b) 4 (c) 8 (d) 16

A carrier signal of 600 V rms with 75% amplitude modulation is applied to 75 ohm antenna. The total side band power (in watts) is  A) 4800 B) 450 C) 950 D) 1350

What is resonance of an antenna?

An antenna located in a city is a source of radio waves. How much time does it take the wave to reach a town 12,000 km away from the city?  a. 36 s b. 20 us c. 20 ms d. 40 ms

When an antenna of input resistance 73 ohm is connected to a 50-ohm line and if the losses are ignored then its efficiency will be nearly   (A) 0.19 (B) 0.81 (C) 0.97 (D) 1.19

In an axial mode operation of a helical antenna, maximum field radiated by the antenna is :  A) along the axis of the helical B) in a plane normal to the helix antenna axis C) in both axial and normal planes D) None of the above

The effect of increasing the length of air gap in an induction motor is to increase the (a) power factor (b) speed (c) magnetising current (d) air gap flux

The line of sight communication requires transmit and receive antenna to face each other. If the transmit antenna is vertically polarized, for the best reception the receive antenna should be:  (1) Horizontally polarized (2) Vertically polarized (3) At 45° with respect to the horizontal polarization (4) At 45° with respect to the vertical polarization

Adaptive array antenna is superior to switched beam antenna because: (A) It optimizes the power radiated (B) It has simpler architecture (C) It has low bandwidth (D) It has low backlobe

If both the number of turns and core length of an inductive coil are doubled, then its self inductance will be (a) halved (b) doubled (c) quadrupled (d) unaffected

What is the function of an electrical filter ?

The moving system of an indicating type of electrical instrument is subjected to (a) a deflecting torque (b) a controlling torque (c) a damping torque (d) All of the above

Continuity of an electrical circuit is usually checked by

Armature of an electrical machine is the (A) stator part of the machine (B) rotor part of the machine (C) yoke of the machine (D) none of these

Which of the following is not an electrical quantity? A. Voltage B. Current C. Distance D. Power

Power factor of an electrical circuit is equal to?

What is the definition of an electrical system?

Find the noise factor for an antenna at 27°C with equivalent noise temperature 30°K: (1) 20 (2) 100 (3) 300 (4) 1.1

For an antenna to be frequency-independent, it should expand or contract in proportion to the  (a) gain (b) directivity (c) wavelength (d) impedance

Choose the most appropriate statement (A) An antenna can radiate only HF signals (B) An antenna can radiate and receive HF signals (C) An antenna can receive only HF signals (D) An antenna can receive and transmit simultaneously HF signals

Electrical isolation circuit is required between power electronic devices and its gated-pulse generating circuit. The following are the possible ways of providing isolation.  P. Pulse transformer  Q. Optical isolators  R. Electro-mechanical relay  S. Capacitive coupling  The effective way of accomplishing isolation is by providing  A) P and Q B) P, Q and S C) P and R D) P, Q, R and S

An _____________is a network of electrical components used to supply, transfer and use electric power:  (A) Electric power system (B) Electric power (C) All of the above (D) None of the above

In an alternator if the winding is short pitched by 60 electrical degrees, its pitch factor will be: A) 1.0 B) 0.866 C) 0.75 D) 0.50

A circuit breaker is designed to protect an electrical circuit from damage caused by :  (A) Over load (B) Short circuit (C) Over current (D) All of the above

When an alternating current passes through an ohmic resistance the electrical power converted into heat is?

What is a node in an electrical circuit?

A 10 km long line has a characteristic impedance of 400 ohms. If line length is 100 km, the characteristic impedance is: (1) 4000 Ω (2) 400 Ω (3) 40 Ω (4) 4 Ω

If the distance of screen from a CRT to center of deflection plates is 15 cm, the length of deflection plates is 2 cm, the distance between the plates is 1 cm and accelerating voltage is 500 V, deflection sensitivity is   (a) 33.2 V/cm (b) 0.03 cm/V (c) 66.4 V/cm (d) 0.015 cm/V