One Stop GATE Forum: ECE GATE sample paper

Message


   

1
          The phase velocity of an electromagnetic wave
            propagating in a hollow metallic rectangular waveguide in the TE₁₀
            mode is
        
        
          Options
          
            
                
              
                  A) equal to its group velocity
                  B) less than the velocity of light in free space
                
                
                  C) equal to the velocity of light in free space
                  D) greater than the velocity of light in free space
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          D
        
        
          

        
        
          2
          A device with input x(t) and output y(t) is
            characterized by:   y(t) = x²(t).

            An FM signal with frequency deviation of 90 kHz and modulating
            signal bandwidth of 5 kHz is applied to this device. The bandwidth
            of the output signal is

             
        
        
          Options
          
            
                
              
                  A) 370 kHz  
                  B) 190 kHz 
                
                
                  C) 380kHz 
                  D) 95kHz
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          C
        
        
          

        
        
          3
          For a signal x(t) the fourier transform is X(f).
            Then the inverse Fourier transform of X(3f + 2) is given by
        
        
          Options
          
            
                
              
                  A)
                    
                        
                      
                          1
                        
                        
                          2
                        
                      
                    
                    x(
                    
                        
                      
                          t
                        
                        
                          2
                        
                      
                    
                    )e^(j3p t) 
                  B)
                    
                        
                      
                          1
                        
                        
                          3
                        
                      
                    
                    x(
                    
                        
                      
                          t
                        
                        
                          3
                        
                      
                    
                    )e^-j4pt/3
                
                
                  C) 3x(3t)e^-j4p t 
                  D) x(3t+2)
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          B
        
        
          

        
        
          4
          The Fourier transform of a conjugate symmetric
            function is always

          
        
        
          Options
          
            
                
              
                  A) imaginary 
                  B) conjugate anti-symmetric 

                  
                
                
                  C) real
                  D) conjugate symmetric
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          C
        
        
          

        
        
          5
          
            A 1 kHz sinusoidal signal is ideally sampled at 1500 samples/sec
            and the sampled signal is passed through an, ideal low-pass filter
            with cut-off frequency 800 Hz.

            The output signal has the frequency
          
        
        
          Options
          
            
                
              
                  A) zero Hz
                  B) 0.75 kHz
                
                
                  C) 0.5 kHz
                  D) 0.25 kHz
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          C
        
        
          

        
        
          6
          An ideal op-amp is an ideal

          
        
        
          Options
          
            
                
              
                  A) voltage controlled current source 
                  B) voltage controlled voltage source

                  
                
                
                  C) current controlled current source 
                  D) current controlled voltage source

                  
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          B
        
        
          

        
        
          7
          A Boolean function f of two variables x and y
            is defined as follows:

            f(0,0) = f(0,1) = f(1, 1) = 1;   f(1,0) = 0

            Assuming complements of x and y are not available, a minimum cost
            solution for realizing fusing only 2-input NOR gates and 2-input OR
            gates (each having unit cost) would have a total cost of
        
        
          Options
          
            
                
              
                  A) 1 unit
                  B) 4 unit
                
                
                  C) 3 unit
                  D) 2 unit
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          D
        
        
          

        
        
          8
          
            The impulse response h[n] of a linear time-invariant system is
            given by

            h[n] = u[n + 3] + u[n - 2] - 2u[n-7]

            where u[n] is the unit step sequence. The above system is
          
        
        
          Options
          
            
                
              
                  A) stable but not causal                  
                  B) stable and causal
                
                
                  C) causal but unstable           
                  D) unstable and not causal
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          A
        
        
          

        
        
          9
          The cascade amplifier is a multistage
            configuration of
        
        
          Options
          
            
                
              
                  A) CC-CB
                  B) CE-CB
                
                
                  C) CB-CC
                  D) CE-CC
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          B
        
        
          

        
        
          10
          A 1 mW video signal having a bandwidth of 100
            MHz is transmitted to a receiver through a cable that has 40 dB
            loss. If the effective one-sided noise spectral density at the
            receiver is 10^-20 Watt/Hz, then the signal-to-noise ratio
            at the receiver is
        
        
          Options
          
            
                
              
                  A) 50 dB
                  B) 30 dB
                
                
                  C) 40 dB
                  D) 60dB
                
              
            
          
        
        
          

          

        
        
          Correct Answer
          A


One Stop GATE Forum : GATE Previous Years Test Papers - Discuss Here : ECE Papers