TANCET2004(Q11toQ20)

TANCET (Questions from Question Paper for Year 2004)

11. If the Iron loss and full load copper loss for a transformer are  given, then the load at which these two losses  are equal,  is given by

A)                full load x            iron loss              

                              full load copper loss

B)                full load x            (iron loss)²    

                              full load copper loss

C)                full load x           √ iron loss              

                              √ full load copper loss

D)                full load x            √ iron loss              

                             √ full load copper loss

12. The ratio between maximum torque, T_max and full load torque, T_f in an induction motor is given by

A)       T_f     =        2a        

         T_max             (a²+s²)

B)      T_f         =        2      

         T_max            (a²+s²)

C)      T_f        =         2as    

         T_max            (a²+s²)

D)      T_f        =         2s       

        T_max               (a²+s²)

where s is the slip and

a =        rotor resistance per phase      

           standstill reactance per phase

13. The loop transfer function G(s) H{s) of a control system has one pole in the right half of s-plane. The corresponding Nyquist plot encircles (-1 + jo) point by 720° clockwise. The number of closed loop poles which lie in the right half of s-plane Is

A)3          

B)0

C)2                         

14. A. channel coding scheme of 6 dB gain is to  be  incorporated  into  an  uncoded system operating successfully with a transmitter power of 1 W and bandwidth of 24 kHz, without any change in the modulation scheme. The coding system would require a minimum

A) bandwidth of 30 kHz

B) transmitter power of 250 mW

C) transmitter power of 6 W

D) bandwidth of 4 kHz

15.   An   Incoming signal has a carrier frequency of 245 MHz and a bandwidth of 50 kHz. At the receiver front end, it is down converted to 70 MHz by mixing it with a suitable local oscillator and band pass filtering. An image rejection filter would be used to eliminate the frequency component at

A) 140 MHz             

B) 105 MHz

C} 175 MHz              

D) 50 kHz

16.A UJT oscillator circuit has to control trigger angle manually for a  maximum value of 1600 for 50 Hz supply. If C = 0.4F and intrinsic standoff ratio is 0.7(maximum),   the   value of charging resistance should be

A) 18.25 k              

B} 18.36 k

C) 18.45 k            

D) 18.79 k

17. Two two-port networks a and p having ABCD parameters as A_u = 4 = D_a, A_p = 3 = D_, B_a = 5, C_{a = 3}, B_p = 4 and C'p  = 2 arc connected In cascade in the order of a,. The equivalent: A parameter of the combination Is

A)17                          

B)22

C)24                          

D)31

18. The amplifier that is generally used in the signal   conditioning  circuit  of a piezo electric sensor is

A)charge amplifier

B)chopper-stabilized amplifier

C)instrumentation amplifier

D)FET differential amplifier

19.When the change in, resistance of  a  resistance  thermometer  is measured using    a wheatstone   bridge,   pulse excitation technique is used in order to

A)  reduce the error due to lead, resistance variation

B)  reduce the error due to self heating

C)  protect the thermometer   from short circuit

D)  get higher bridge sensitivity

20. When a displacement of 5 mm is given to the core of a linear variable differential transformer, the outputs across the two secondary windings are 3 V and 2.5 V .The sensitivity of LVDT is

A) 0.6 V/mm

B)1.1 V/mm

C)0.1 V/mm

D)10 V/mm

Answer: 11)C   12)C  13)C  14)B  15)B  16)C  17)C  18)A  19)B   20)C