MCQ
An antenna behaves as resonant circuit only when its length is
  • A
    $\frac{\lambda }{2}$
  • B
    $\frac{\lambda }{4}$
  • C
    $\lambda$
  • $\frac{\lambda }{2}$ or integral multiple of $\frac{\lambda }{2}$

Answer

Correct option: D.
$\frac{\lambda }{2}$ or integral multiple of $\frac{\lambda }{2}$
d
(d) Antenna behaves as a resonant circuit when its length is $\frac{\lambda}{2}$ or integral multiple of $\frac{\lambda}{2}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A hypothetical atom has only three energy levels. The ground level has energy, $E_1 = - 8\, eV$. The two excited states have energies, $E_2 = - 6\, eV$ and $E_3 = - 2\, eV$. Then which of the following wavelengths will not be present in the emission spectrum of this atom? .............. $nm$
 (image) Product $A$ is
$A$ particle starts from the point $(0m, 8m)$ and moves with uniform velocity of $3\, \hat i \,m/s$. After $5$ seconds, the angular velocity of the particle about the origin will be :
A thin and uniform rod of mass $M$ and length $L$ is held vertical on a floor with large friction. The rod is released from rest so that it falls by rotating about its contact-point with the floor without slipping. Which of the following statement($s$) is/are correct, when the rod makes an angle $60^{\circ}$ with vertical ? [ $g$ is the acceleration due to gravity]

$(1)$ The radial acceleration of the rod's center of mass will be $\frac{3 g }{4}$

$(2)$ The angular acceleration of the rod will be $\frac{2 g }{ L }$

$(3)$ The angular speed of the rod will be $\sqrt{\frac{3 g}{2 L}}$

$(4)$ The normal reaction force from the floor on the rod will be $\frac{ Mg }{16}$

A zinc ball of radius $1 \,cm$ charged to a potential $-0.5 \,V$. The ball is illuminated by a monochromatic ultraviolet light with a wavelength $290 \,nm$. The photoelectric threshold for zinc is $332 \,nm$. The potential of ball after a prolonged exposure to the ultraviolet is ............. $V$
In the transient current circuit shown, the time constant is
A choke coil is preferred to a $( Rheostat ) $ in $ ac $ circuit as
The mobility of free electron is greater than that of free holes because
The ratio of intensities of two waves are given by $4 : 1.$ The ratio of the amplitudes of the two waves is
Power of a water pump is $ 2 kW. $ If $g = 10\,m/{\sec ^2}$, the amount of water it can raise in one minute to a height of $10 m$  is .............. $liter$