GATE ECE 1998 | Antennas Question 30 | Electromagnetics

GATE ECE 1998

MCQ (Single Correct Answer)

-0.3

An antenna in free space receives 2$$\mu $$ W of power when the incident electric field is 20 m V/m rms. The effective aperture of the antenna is

0.005 $${m^2}$$

0.05 $${m^2}$$

1.885 $${m^2}$$

3.77 $${m^2}$$

GATE ECE 1998

MCQ (Single Correct Answer)

-0.3

The far field of an antenna varies with distance r as

1/r

1 / $${r^2}$$

1 / $${r^3}$$

$${1 \over {\sqrt r }}$$

GATE ECE 1998

MCQ (Single Correct Answer)

-0.3

The vector $$\mathop H\limits^ \to $$ in the far field of an antenna satisfiels

$$\nabla .\,\mathop H\limits^ \to = 0\,\,and\,\,\nabla \times \,\mathop H\limits^ \to = 0\,$$

$$\nabla .\,\mathop H\limits^ \to \ne 0\,\,and\,\,\nabla \times \,\mathop H\limits^ \to \ne 0$$

$$\nabla .\,\mathop H\limits^ \to = 0\,\,and\,\,\nabla \times \,\mathop H\limits^ \to \ne 0\,\,$$

$$\nabla .\,\mathop H\limits^ \to \ne 0\,\,and\,\,\nabla \times \,\mathop H\limits^ \to = 0\,\,$$

GATE ECE 1995

MCQ (Single Correct Answer)

-0.3

An antenna when radiating, has a highly directional radiation pattern. When the antenna is receiving its radiation pattern

is more directive

is less directive

is the same

exhibits no directivity at all

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GATE ECE Subjects

Signals and Systems

Representation of Continuous Time Signal Fourier Series Fourier Transform Continuous Time Signal Laplace Transform Discrete Time Signal Fourier Series Fourier Transform Discrete Fourier Transform and Fast Fourier Transform Discrete Time Signal Z Transform Continuous Time Linear Invariant System Discrete Time Linear Time Invariant Systems Transmission of Signal Through Continuous Time LTI Systems Sampling Transmission of Signal Through Discrete Time Lti Systems Miscellaneous

Network Theory

Network Elements Network Theorems Transient Response Sinusoidal Steady State Response Two Port Networks Network Graphs State Equations For Networks Miscellaneous

Control Systems

Signal Flow Graph and Block Diagram Time Response Analysis Compensators Basic of Control Systems Frequency Response Analysis Stability Root Locus Diagram State Space Analysis

Digital Circuits

Logic Gates Boolean Algebra Analog to Digital and Digital to Analog Converters Sequential Circuits Combinational Circuits Logic Families Number System and Code Convertions Semiconductor Memories

General Aptitude

Verbal Ability Logical Reasoning Numerical Ability

Electronic Devices and VLSI

Semiconductor Physics PN Junction BJT and FET IC Basics and MOSFET

Analog Circuits

Bipolar Junction Transistor FET and MOSFET Oscillators Operational Amplifier 555 Timer Frequency Response Diodes Feedback Amplifier Power Amplifier

Engineering Mathematics

Linear Algebra Calculus Vector Calculus Probability and Statistics Differential Equations Complex Variable Numerical Methods Transform Theory

Microprocessors

Instruction Set and Programming with 8085 Pin Details of 8085 and Interfacing with 8085

Communications

Fundamentals of Information Theory Noise In Digital Communication Analog Communication Systems Digital Communication Systems Random Signals and Noise

Electromagnetics

Waveguides Antennas Miscellaneous Transmission Lines Maxwell Equations Uniform Plane Waves