A radar has a power of 1 kW and is operating | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) Let $d$ be the maximum distance up to which the radar can detect an object on the Earth's surface. From the geometry of the right-angled triangle

Vedclass · Accepted Answer

$80$

Vedclass · Answer

(B) Let $d$ be the maximum distance up to which the radar can detect an object on the Earth's surface. From the geometry of the right-angled triangle $\Delta OAC$ (where $O$ is the center of the Earth,$A$ is the object on the surface,and $C$ is the radar on the mountain top):$OC^2 = AC^2 + OA^2$$(h + R)^2 = d^2 + R^2$$d^2 = (h + R)^2 - R^2$$d^2 = h^2 + 2hR + R^2 - R^2$$d = \sqrt{h^2 + 2hR}$Since $h = 500 \ m = 0.5 \ km$ and $R = 6400 \ km$,$h^2$ is negligible compared to $2hR$.$d \approx \sqrt{2hR} = \sqrt{2 	imes 0.5 	imes 6400} = \sqrt{6400} = 80 \ km$.

$A$ radar has a power of $1 \ kW$ and is operating at a frequency of $10 \ GHz$. It is located on a mountain top of height $500 \ m$. The maximum distance up to which it can detect an object located on the surface of the earth (Radius of earth $= 6.4 \times 10^6 \ m$) is ....... $km$.

Similar Questions

If the maximum and minimum amplitudes of a modulated wave are $25 \ V$ and $5 \ V$ respectively,then the modulation index is

$A$ speech signal of $3 \text{ kHz}$ is used to modulate a carrier signal of frequency $1 \text{ MHz}$ using amplitude modulation. The frequencies of the sidebands will be:

The required height of a $TV$ tower which can cover the population of $6.03$ lakh is $h$. If the average population density is $100$ per square $km$ and the radius of the Earth is $6400 \, km$,then the value of $h$ will be $... \, m$.

What should be the height of the transmitting antenna and the population covered if the television telecast is to cover a radius of $150 \, km$? The average population density around the tower is $2000 \, / km^2$ and the value of $R_e = 6.5 \times 10^6 \, m$.

When the modulating frequency is doubled, the modulation index is halved and the modulating voltage remains constant, the modulation system is

Vedclass Test Series

Exam Paper Generator

Online Exam Module