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This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Antennas knowledge and support exam preparation. Choose a topic below to get started.
1. |
Relation between gradient of refractive index with height and dielectric constant gradient is ____________ |
A. | \(\frac{dϵ_r}{dH}=2n \frac{dn}{dH}\) |
B. | \(\frac{dϵ_r}{dH}=n \frac{dn}{dH}\) |
C. | \(\frac{dϵ_r}{dH}=2n/\frac{dn}{dH}\) |
D. | \(\frac{dϵ_r}{dH}=-2n \frac{dn}{dH}\) |
Answer» B. \(\frac{dϵ_r}{dH}=n \frac{dn}{dH}\) | |
2. |
Refractive index is directly proportion to ___________ |
A. | \(\sqrt{ϵ_r}\) |
B. | \(1/\sqrt{ϵ_r} \) |
C. | ϵr |
D. | 1/ϵr |
Answer» B. \(1/\sqrt{ϵ_r} \) | |
3. |
On which of the following the refractivity depends on? |
A. | Air pressure |
B. | Water pressure |
C. | Temperature |
D. | Air pressure, water pressure and temperature |
Answer» E. | |
4. |
Expression for refractivity is given by ___________ |
A. | N=(n-1)×106 |
B. | N=(n-1)×10-6 |
C. | N=1/(n-1) |
D. | N=\(\frac{1}{n-1}\)×10-6 |
Answer» B. N=(n-1)×10-6 | |
5. |
What is the effective radius factor when radius of curvature is 4 times the radius of earth? |
A. | 4 |
B. | 4/3 |
C. | 3 |
D. | 3/4 |
Answer» C. 3 | |
6. |
Expression for effective radius factor k in terms of radius of curvature rc and radius of earth re? |
A. | \(k=\frac{1}{1-\frac{r_c}{r_e}} \) |
B. | \(k=\frac{1}{1-\frac{r_e}{r_c}} \) |
C. | \(k= 1-\frac{r_e}{r_c} \) |
D. | \(k= 1-\frac{r_c}{r_e} \) |
Answer» C. \(k= 1-\frac{r_e}{r_c} \) | |
7. |
What is the standard value for the radius of curvature rc to be equal to the radius of earth re? |
A. | rc=4re |
B. | rc=\(\frac{4r_e}{3}\) |
C. | rc=re |
D. | rc=\(\frac{1}{4}\) re |
Answer» B. rc=\(\frac{4r_e}{3}\) | |
8. |
Gradient of refractive index is ____________ |
A. | Change in the refractivity with respect to height |
B. | Change in the height with respect to refractivity |
C. | Change in the refractivity with respect to Pressure |
D. | Change in the refractivity with respect to temperature |
Answer» B. Change in the height with respect to refractivity | |
9. |
The expression for refractivity in terms of the Pressure and temperature coefficient is given by ____________ |
A. | \(\frac{77.6}{T}P+4810 \frac{e}{T} \) |
B. | \(\frac{77.6}{P}T+4810 \frac{e}{T} \) |
C. | \(\frac{77.6}{P}T+4810 \frac{T}{e} \) |
D. | \(\frac{77.6}{T}P+4810 \frac{T}{e} \) |
Answer» B. \(\frac{77.6}{P}T+4810 \frac{e}{T} \) | |
10. |
Which of the following varies with the refractive index in the atmosphere? |
A. | Radio horizon |
B. | Optical horizon |
C. | Line of sight (LOS) |
D. | Both radio horizon and LOS |
Answer» B. Optical horizon | |