58751. The line of sight communication requires that transmit and receive antennas to face each other. If the transmit antenna is vertically polarized, for the best reception the receive antenna should be
58752. An antenna has 40 Ω resistance and 60 Ω radiation resistance. The efficiency of the antenna is
58753. The duration of sunspot cycle is
58754. Electromagnetic cavity resonators (energy storage devices) are used in
58755. Waveguides are generally used above
58756. Maximum power transfer will take place in a practical antenna if (XL = Load Reactance, XA Antenna Reactance)
58757. Which type of fading causes serious distortion of modulated signal?
58758. Tropospheric scatter is used with frequencies in the
58759. A Yagi antenna has a driven antenna
58760. The minimum height of outer atmosphere is
58761. An electric charge Q is placed in a dielectric medium which of the following quantities are independent of the dielectric constant ε of the medium
58762. A square corner reflector is used in
58763. The wave in wave guide has
58764. While determining antenna height for terrestrial microwaves links, the effect of refraction from the atmosphere is taken care of by considering the effective curvature of the earth to be
58765. A T.V. station works at 300 MHz and radiates 100 kW of power. This signal received at a distance of 200 km will be
58766. The power gain of a half-wave dipole with respect to an isotropic radiator is
58767. In an impedance smith chart, a clockwise movement along a constant resistance circle gives rise to
58768. When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called
58769. The main disadvantage of the two-hole directional coupler is
58770. The radiation pattern of a parabola antenna is
58771. Swarajya was declared as the goal of the congress at its session in 1906 at?
58772. In microwave communication links, when fading due to rain attenuation occurs then technique adopted for solving the problem would include
58773. Due to which of the following reasons a lightning conductor on top of a building is made into a pointed spike?
58774. The virtual height of an ionospheric layer is __________ true height
58775. The divergence of a vector is a scalar, while the curl of a vector is another
58776. An open wire transmission line having a characteristic impedance of 600 ohms is terminated by a resistive load of 900 Ω. The standing wave ratio will be
58777. The skip distance is the maximum distance upto which ionospheric reflection is possible.
58778. Maxwell's divergence equation for the magnetic field is given as
58779. Which antenna is a wideband antenna?
58780. The radiation pattern of loop antenna is
58781. Maxwell's curl equation for the static electric field E can be expressed as
58782. The unit of ∇ x H is
58783. The relative permittivity of the ionosphere at ratio frequencies is
58784. Tropospheric scatter propagation is not subject to any fading.
58785. The attenuation in waveguide above to cut off frequency
58786. VSWR is related with reflection co-efficient as
58787. When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon
58788. A square corner reflector is used in which of the following?
58789. The moment of inertia of a triangular section with base ‘b’ and height’h’about an axis through the centre of gravity and parallel to the base is given as
58790. If the resultant of two forces has the same magnitude as either of the forces,then the angle between the forces is
58791. The direction of vectors gives the direction of propagation of electromagnetic waves
58792. According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when
58793. A medium is divided into regions I and II about x = 0 plane, as shown in the figure below.
An EM wave with electric field is incident normally on the interface from region-I.
The electric field E2 in region-II at the interface is
58794. The static electric field in a conductor is
58795. The propagation constant of a transmission line is
58796. In a perfect conductor the incident and reflected wave combine to produce
58797. MUF is highest in periods of greatest sunspot activity.
58798. A transmission line has primary constants R, L, G and C and secondary constant z0 and γ = (a + Jβ). If the line is loss less, then
58799. Which of the following is multiband HF receiving antenna?