Page 1 GATE EE - 1995 SECTION - A 1. This question has TWENTY-FIVE statements. Each statement is accompanied by four answers of which only one is correct. Indicate the correct answer as A, B, C or D on the first page of the answer book. Each statement carries ONE mark. 1.1 The impulse response of an initially relaxed linear system is ( ) 2 . t e U t - To produce a response of ( ) 2 , t te U t - the input must be equal to (a) ( ) 2 t e U t - (b) ( ) 2 1 2 t e U t - (c) ( ) 2t e U t - (d) ( ) t e U t - 1.2 The closed loop transfer function of a control system is given by ( ) ( ) ( ) ( )( ) 2 1 2 1 C s s R s s s - = + + For a unit step input the output is (a) 2 3 4 1 t t e e - - - + - (b) 2 3 4 1 t t e e - - - - + (c) zero (d) infinity 1.3 The Laplace transformation of ( ) ( ) is . f t F s Given ( ) 2 2 , F s s ? ? = + the final value of ( ) f t is: (a) infinity (b) zero (c) one (d) none of the above 1.4 A system is described by the state equation . XX AX BU = + The output is given by Y CX = where 4 1 1 , , 1, 0 . 3 1 1 A B C - - ? ? ? ? = = = ? ? ? ? ? ? ? ? - ? ? ? ? Transfer function ( ) G s of the system is: (a) 2 5 7 s s s + + (b) 2 1 5 7 s s + + (c) 2 3 2 s s s + + (d) 2 1 3 2 s s + + 1.5 The rms value of the periodic waveform ( ), e t shown in figure is: (a) 3 2 A (b) 2 3 A (c) 1 3 A (d) 2A T/2 T t +A - A S(t) Page 2 GATE EE - 1995 SECTION - A 1. This question has TWENTY-FIVE statements. Each statement is accompanied by four answers of which only one is correct. Indicate the correct answer as A, B, C or D on the first page of the answer book. Each statement carries ONE mark. 1.1 The impulse response of an initially relaxed linear system is ( ) 2 . t e U t - To produce a response of ( ) 2 , t te U t - the input must be equal to (a) ( ) 2 t e U t - (b) ( ) 2 1 2 t e U t - (c) ( ) 2t e U t - (d) ( ) t e U t - 1.2 The closed loop transfer function of a control system is given by ( ) ( ) ( ) ( )( ) 2 1 2 1 C s s R s s s - = + + For a unit step input the output is (a) 2 3 4 1 t t e e - - - + - (b) 2 3 4 1 t t e e - - - - + (c) zero (d) infinity 1.3 The Laplace transformation of ( ) ( ) is . f t F s Given ( ) 2 2 , F s s ? ? = + the final value of ( ) f t is: (a) infinity (b) zero (c) one (d) none of the above 1.4 A system is described by the state equation . XX AX BU = + The output is given by Y CX = where 4 1 1 , , 1, 0 . 3 1 1 A B C - - ? ? ? ? = = = ? ? ? ? ? ? ? ? - ? ? ? ? Transfer function ( ) G s of the system is: (a) 2 5 7 s s s + + (b) 2 1 5 7 s s + + (c) 2 3 2 s s s + + (d) 2 1 3 2 s s + + 1.5 The rms value of the periodic waveform ( ), e t shown in figure is: (a) 3 2 A (b) 2 3 A (c) 1 3 A (d) 2A T/2 T t +A - A S(t) GATE EE - 1995 1.6 A spherical conductor of radius â€˜aâ€™ with charge â€˜qâ€™ is placed concentrically inside an uncharged and unearthed spherical conducting shell of inner and outer radii 1 2 and r r respectively. Taking potential to be zero at infinity, the potential at any point P within the shell ( ) 1 2 r r r < < will be: (a) 0 4 q r pe (b) 0 4 q a pe (c) 0 2 4 q r pe (d) 0 1 4 q r pe 1.7 A monochromatic plane electromagnetic wave travels in vacuum in the position x direction (x, y, z system of coordinates). The electric and magnetic fields can be expressed as (a) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - (b) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - ? ? ? ? (c) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - - (d) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - - ? ? ? ? 1.8 Supply to one terminal of a delta-wye connected three-phase core type transformer which is on no-load, fails. Assuming magnetic circuit symmetry, voltages on the secondary side will be: (a) 230, 230, 115 (b) 230, 115, 115 (c) 345, 115, 115 (d) 345, 0, 345 1.9 An induction motor is fed from a balanced three phase supply at rated voltage and frequency through a bank of three single phase transformers connected in delta-delta. One unit of the bank develops fault and is removed. Then, (a) single phasing will occur and the machine fails to start (b) single phasing will not occur but the motor terminal voltages will become unbalanced and the machine can be loaded to the extent of 57.7% of its rating. (c) the machine can be loaded to the extent of 57.7% of its rating with balanced supply at its terminals. P q r r 2 r 1 a Page 3 GATE EE - 1995 SECTION - A 1. This question has TWENTY-FIVE statements. Each statement is accompanied by four answers of which only one is correct. Indicate the correct answer as A, B, C or D on the first page of the answer book. Each statement carries ONE mark. 1.1 The impulse response of an initially relaxed linear system is ( ) 2 . t e U t - To produce a response of ( ) 2 , t te U t - the input must be equal to (a) ( ) 2 t e U t - (b) ( ) 2 1 2 t e U t - (c) ( ) 2t e U t - (d) ( ) t e U t - 1.2 The closed loop transfer function of a control system is given by ( ) ( ) ( ) ( )( ) 2 1 2 1 C s s R s s s - = + + For a unit step input the output is (a) 2 3 4 1 t t e e - - - + - (b) 2 3 4 1 t t e e - - - - + (c) zero (d) infinity 1.3 The Laplace transformation of ( ) ( ) is . f t F s Given ( ) 2 2 , F s s ? ? = + the final value of ( ) f t is: (a) infinity (b) zero (c) one (d) none of the above 1.4 A system is described by the state equation . XX AX BU = + The output is given by Y CX = where 4 1 1 , , 1, 0 . 3 1 1 A B C - - ? ? ? ? = = = ? ? ? ? ? ? ? ? - ? ? ? ? Transfer function ( ) G s of the system is: (a) 2 5 7 s s s + + (b) 2 1 5 7 s s + + (c) 2 3 2 s s s + + (d) 2 1 3 2 s s + + 1.5 The rms value of the periodic waveform ( ), e t shown in figure is: (a) 3 2 A (b) 2 3 A (c) 1 3 A (d) 2A T/2 T t +A - A S(t) GATE EE - 1995 1.6 A spherical conductor of radius â€˜aâ€™ with charge â€˜qâ€™ is placed concentrically inside an uncharged and unearthed spherical conducting shell of inner and outer radii 1 2 and r r respectively. Taking potential to be zero at infinity, the potential at any point P within the shell ( ) 1 2 r r r < < will be: (a) 0 4 q r pe (b) 0 4 q a pe (c) 0 2 4 q r pe (d) 0 1 4 q r pe 1.7 A monochromatic plane electromagnetic wave travels in vacuum in the position x direction (x, y, z system of coordinates). The electric and magnetic fields can be expressed as (a) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - (b) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - ? ? ? ? (c) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - - (d) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - - ? ? ? ? 1.8 Supply to one terminal of a delta-wye connected three-phase core type transformer which is on no-load, fails. Assuming magnetic circuit symmetry, voltages on the secondary side will be: (a) 230, 230, 115 (b) 230, 115, 115 (c) 345, 115, 115 (d) 345, 0, 345 1.9 An induction motor is fed from a balanced three phase supply at rated voltage and frequency through a bank of three single phase transformers connected in delta-delta. One unit of the bank develops fault and is removed. Then, (a) single phasing will occur and the machine fails to start (b) single phasing will not occur but the motor terminal voltages will become unbalanced and the machine can be loaded to the extent of 57.7% of its rating. (c) the machine can be loaded to the extent of 57.7% of its rating with balanced supply at its terminals. P q r r 2 r 1 a GATE EE - 1995 (d) the machine can be loaded to the extent of 2 66 % 3 with balanced supply at its terminals. 1.10 A synchronous motor on load draws a current at a leading power factor angle f. If the internal power factor angle â€“ which is the phase angle between the excitation e.m.f. and the current in the time phasor diagram is O, then the air gap excitation m.m.f lags the armature m.m.f by (a) ? (b) 2 p ? + (c) 2 p ? - (d) ? + F 1.11 A differentially compounded d.c. motor with interpoles and with brushes on the neutral axis is to be driven as a generator in the same direction with the same polarity of the terminal voltage. It will then (a) be a cumulatively compound generator but the interpole coil connections are to be reversed (b) be a cumulatively compounded generator without reversing the interpole coil connections. (c) be a differentially compounded generator without reversing the interpole coil connections (d) be a differentially compounded generator but the interpole coil connections are to be reversed. 1.12 The surge impedance of a 400 km long overhead transmission line is 400 ohms. For a 200 km length of the same line, the surge impedance will be (a) 200 O (b) 800 O (c) 400 O (d) 100 O 1.13 The insulation level of a 400 kV EHV overhead transmission line is decided on the basis of (a) lightning over voltage (b) switching over voltage (c) corona inception voltage (d) radio and TV interference 1.14 In order to have a lower cost of electrical energy generation, (a) the load factor and diversity factor should be low (b) the load factor should be low but diversity factor should be high (c) the load factor should be high but diversity factor should be low (d) the load factor and diversity factor should be high 1.15 The main criterion for selection of the size of a distribution for a radial distribution system is: (a) voltage drop (b) corona loss (c) temperature rise (d) capital cost Page 4 GATE EE - 1995 SECTION - A 1. This question has TWENTY-FIVE statements. Each statement is accompanied by four answers of which only one is correct. Indicate the correct answer as A, B, C or D on the first page of the answer book. Each statement carries ONE mark. 1.1 The impulse response of an initially relaxed linear system is ( ) 2 . t e U t - To produce a response of ( ) 2 , t te U t - the input must be equal to (a) ( ) 2 t e U t - (b) ( ) 2 1 2 t e U t - (c) ( ) 2t e U t - (d) ( ) t e U t - 1.2 The closed loop transfer function of a control system is given by ( ) ( ) ( ) ( )( ) 2 1 2 1 C s s R s s s - = + + For a unit step input the output is (a) 2 3 4 1 t t e e - - - + - (b) 2 3 4 1 t t e e - - - - + (c) zero (d) infinity 1.3 The Laplace transformation of ( ) ( ) is . f t F s Given ( ) 2 2 , F s s ? ? = + the final value of ( ) f t is: (a) infinity (b) zero (c) one (d) none of the above 1.4 A system is described by the state equation . XX AX BU = + The output is given by Y CX = where 4 1 1 , , 1, 0 . 3 1 1 A B C - - ? ? ? ? = = = ? ? ? ? ? ? ? ? - ? ? ? ? Transfer function ( ) G s of the system is: (a) 2 5 7 s s s + + (b) 2 1 5 7 s s + + (c) 2 3 2 s s s + + (d) 2 1 3 2 s s + + 1.5 The rms value of the periodic waveform ( ), e t shown in figure is: (a) 3 2 A (b) 2 3 A (c) 1 3 A (d) 2A T/2 T t +A - A S(t) GATE EE - 1995 1.6 A spherical conductor of radius â€˜aâ€™ with charge â€˜qâ€™ is placed concentrically inside an uncharged and unearthed spherical conducting shell of inner and outer radii 1 2 and r r respectively. Taking potential to be zero at infinity, the potential at any point P within the shell ( ) 1 2 r r r < < will be: (a) 0 4 q r pe (b) 0 4 q a pe (c) 0 2 4 q r pe (d) 0 1 4 q r pe 1.7 A monochromatic plane electromagnetic wave travels in vacuum in the position x direction (x, y, z system of coordinates). The electric and magnetic fields can be expressed as (a) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - (b) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - ? ? ? ? (c) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - - (d) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - - ? ? ? ? 1.8 Supply to one terminal of a delta-wye connected three-phase core type transformer which is on no-load, fails. Assuming magnetic circuit symmetry, voltages on the secondary side will be: (a) 230, 230, 115 (b) 230, 115, 115 (c) 345, 115, 115 (d) 345, 0, 345 1.9 An induction motor is fed from a balanced three phase supply at rated voltage and frequency through a bank of three single phase transformers connected in delta-delta. One unit of the bank develops fault and is removed. Then, (a) single phasing will occur and the machine fails to start (b) single phasing will not occur but the motor terminal voltages will become unbalanced and the machine can be loaded to the extent of 57.7% of its rating. (c) the machine can be loaded to the extent of 57.7% of its rating with balanced supply at its terminals. P q r r 2 r 1 a GATE EE - 1995 (d) the machine can be loaded to the extent of 2 66 % 3 with balanced supply at its terminals. 1.10 A synchronous motor on load draws a current at a leading power factor angle f. If the internal power factor angle â€“ which is the phase angle between the excitation e.m.f. and the current in the time phasor diagram is O, then the air gap excitation m.m.f lags the armature m.m.f by (a) ? (b) 2 p ? + (c) 2 p ? - (d) ? + F 1.11 A differentially compounded d.c. motor with interpoles and with brushes on the neutral axis is to be driven as a generator in the same direction with the same polarity of the terminal voltage. It will then (a) be a cumulatively compound generator but the interpole coil connections are to be reversed (b) be a cumulatively compounded generator without reversing the interpole coil connections. (c) be a differentially compounded generator without reversing the interpole coil connections (d) be a differentially compounded generator but the interpole coil connections are to be reversed. 1.12 The surge impedance of a 400 km long overhead transmission line is 400 ohms. For a 200 km length of the same line, the surge impedance will be (a) 200 O (b) 800 O (c) 400 O (d) 100 O 1.13 The insulation level of a 400 kV EHV overhead transmission line is decided on the basis of (a) lightning over voltage (b) switching over voltage (c) corona inception voltage (d) radio and TV interference 1.14 In order to have a lower cost of electrical energy generation, (a) the load factor and diversity factor should be low (b) the load factor should be low but diversity factor should be high (c) the load factor should be high but diversity factor should be low (d) the load factor and diversity factor should be high 1.15 The main criterion for selection of the size of a distribution for a radial distribution system is: (a) voltage drop (b) corona loss (c) temperature rise (d) capital cost GATE EE - 1995 1.16 The insulation resistance of a cable of length 10 km is 1 MO. For a length of 100 km of the same cable, the insulation resistance will be (a) 1 MO (b) 10 MO (c) 0.1 MO (d) 0.01 MO 1.17 A 1 3 2 digit, 2 V full scale slope ADC has its integration time set to 300 ms. if the input to the ADC is ( ) 1 1sin314 , t V + then the ADC output will be (a) 1.000 (b) 1.999 (c) 1.414 (d) 1.500 1.18 Four ammeters M1, M2, M3 and M4 with the following specifications are available. Instrument Type Full scale value (A) Accuracy % of FS M1 1 3 2 digit dual slope 20 ±0.10 M2 PMMC 10 ±0.20 M3 Electrodynamic 5 ±0.50 M4 Moving iron 1 ±1.00 A current of 1A is to be measured. To obtain minimum error in the reading, one should select meter (a) M1 (b) M2 (c) M3 (d) M4 1.19. A Kelvin double bridge is best suited for the measurement of (a) inductance (b) capacitance (c) low resistance (d) high resistance 1.20. In an 8085 microprocessor, after the execution of XRA A instruction (a) the carry flag is set (b) the accumulator contains H FF (c) the zero flag is set (d) the accumulator contents are shifted left by one bit 1.21. A certain oscilloscope with 4 cm by 4 cm screen has its own sweep output fed to its input. If the x and y sensitivities are same, the oscilloscope will display a (a) triangular wave (b) diagonal line (c) sine wave (d) circle 1.22. A single phase diode bridge rectifier supplies a highly inductive load. The load current can be assumed to be ripple free. The ac supply side current waveform will be: (a) sinusoidal (b) constant dc (c) square (d) triangular Page 5 GATE EE - 1995 SECTION - A 1. This question has TWENTY-FIVE statements. Each statement is accompanied by four answers of which only one is correct. Indicate the correct answer as A, B, C or D on the first page of the answer book. Each statement carries ONE mark. 1.1 The impulse response of an initially relaxed linear system is ( ) 2 . t e U t - To produce a response of ( ) 2 , t te U t - the input must be equal to (a) ( ) 2 t e U t - (b) ( ) 2 1 2 t e U t - (c) ( ) 2t e U t - (d) ( ) t e U t - 1.2 The closed loop transfer function of a control system is given by ( ) ( ) ( ) ( )( ) 2 1 2 1 C s s R s s s - = + + For a unit step input the output is (a) 2 3 4 1 t t e e - - - + - (b) 2 3 4 1 t t e e - - - - + (c) zero (d) infinity 1.3 The Laplace transformation of ( ) ( ) is . f t F s Given ( ) 2 2 , F s s ? ? = + the final value of ( ) f t is: (a) infinity (b) zero (c) one (d) none of the above 1.4 A system is described by the state equation . XX AX BU = + The output is given by Y CX = where 4 1 1 , , 1, 0 . 3 1 1 A B C - - ? ? ? ? = = = ? ? ? ? ? ? ? ? - ? ? ? ? Transfer function ( ) G s of the system is: (a) 2 5 7 s s s + + (b) 2 1 5 7 s s + + (c) 2 3 2 s s s + + (d) 2 1 3 2 s s + + 1.5 The rms value of the periodic waveform ( ), e t shown in figure is: (a) 3 2 A (b) 2 3 A (c) 1 3 A (d) 2A T/2 T t +A - A S(t) GATE EE - 1995 1.6 A spherical conductor of radius â€˜aâ€™ with charge â€˜qâ€™ is placed concentrically inside an uncharged and unearthed spherical conducting shell of inner and outer radii 1 2 and r r respectively. Taking potential to be zero at infinity, the potential at any point P within the shell ( ) 1 2 r r r < < will be: (a) 0 4 q r pe (b) 0 4 q a pe (c) 0 2 4 q r pe (d) 0 1 4 q r pe 1.7 A monochromatic plane electromagnetic wave travels in vacuum in the position x direction (x, y, z system of coordinates). The electric and magnetic fields can be expressed as (a) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - (b) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - ? ? ? ? (c) ( ) ( ) ( ) ( ) 0 0 , cos , cos y z E x t E kx t a H x t H kx t a ? ? = - = - - (d) ( ) ( ) ( ) 0 0 , cos , cos 2 y z E x t E kx t a H x t H kx t a ? p ? = - ? ? = - - - ? ? ? ? 1.8 Supply to one terminal of a delta-wye connected three-phase core type transformer which is on no-load, fails. Assuming magnetic circuit symmetry, voltages on the secondary side will be: (a) 230, 230, 115 (b) 230, 115, 115 (c) 345, 115, 115 (d) 345, 0, 345 1.9 An induction motor is fed from a balanced three phase supply at rated voltage and frequency through a bank of three single phase transformers connected in delta-delta. One unit of the bank develops fault and is removed. Then, (a) single phasing will occur and the machine fails to start (b) single phasing will not occur but the motor terminal voltages will become unbalanced and the machine can be loaded to the extent of 57.7% of its rating. (c) the machine can be loaded to the extent of 57.7% of its rating with balanced supply at its terminals. P q r r 2 r 1 a GATE EE - 1995 (d) the machine can be loaded to the extent of 2 66 % 3 with balanced supply at its terminals. 1.10 A synchronous motor on load draws a current at a leading power factor angle f. If the internal power factor angle â€“ which is the phase angle between the excitation e.m.f. and the current in the time phasor diagram is O, then the air gap excitation m.m.f lags the armature m.m.f by (a) ? (b) 2 p ? + (c) 2 p ? - (d) ? + F 1.11 A differentially compounded d.c. motor with interpoles and with brushes on the neutral axis is to be driven as a generator in the same direction with the same polarity of the terminal voltage. It will then (a) be a cumulatively compound generator but the interpole coil connections are to be reversed (b) be a cumulatively compounded generator without reversing the interpole coil connections. (c) be a differentially compounded generator without reversing the interpole coil connections (d) be a differentially compounded generator but the interpole coil connections are to be reversed. 1.12 The surge impedance of a 400 km long overhead transmission line is 400 ohms. For a 200 km length of the same line, the surge impedance will be (a) 200 O (b) 800 O (c) 400 O (d) 100 O 1.13 The insulation level of a 400 kV EHV overhead transmission line is decided on the basis of (a) lightning over voltage (b) switching over voltage (c) corona inception voltage (d) radio and TV interference 1.14 In order to have a lower cost of electrical energy generation, (a) the load factor and diversity factor should be low (b) the load factor should be low but diversity factor should be high (c) the load factor should be high but diversity factor should be low (d) the load factor and diversity factor should be high 1.15 The main criterion for selection of the size of a distribution for a radial distribution system is: (a) voltage drop (b) corona loss (c) temperature rise (d) capital cost GATE EE - 1995 1.16 The insulation resistance of a cable of length 10 km is 1 MO. For a length of 100 km of the same cable, the insulation resistance will be (a) 1 MO (b) 10 MO (c) 0.1 MO (d) 0.01 MO 1.17 A 1 3 2 digit, 2 V full scale slope ADC has its integration time set to 300 ms. if the input to the ADC is ( ) 1 1sin314 , t V + then the ADC output will be (a) 1.000 (b) 1.999 (c) 1.414 (d) 1.500 1.18 Four ammeters M1, M2, M3 and M4 with the following specifications are available. Instrument Type Full scale value (A) Accuracy % of FS M1 1 3 2 digit dual slope 20 ±0.10 M2 PMMC 10 ±0.20 M3 Electrodynamic 5 ±0.50 M4 Moving iron 1 ±1.00 A current of 1A is to be measured. To obtain minimum error in the reading, one should select meter (a) M1 (b) M2 (c) M3 (d) M4 1.19. A Kelvin double bridge is best suited for the measurement of (a) inductance (b) capacitance (c) low resistance (d) high resistance 1.20. In an 8085 microprocessor, after the execution of XRA A instruction (a) the carry flag is set (b) the accumulator contains H FF (c) the zero flag is set (d) the accumulator contents are shifted left by one bit 1.21. A certain oscilloscope with 4 cm by 4 cm screen has its own sweep output fed to its input. If the x and y sensitivities are same, the oscilloscope will display a (a) triangular wave (b) diagonal line (c) sine wave (d) circle 1.22. A single phase diode bridge rectifier supplies a highly inductive load. The load current can be assumed to be ripple free. The ac supply side current waveform will be: (a) sinusoidal (b) constant dc (c) square (d) triangular GATE EE - 1995 1.23. A dc to dc transistor chopper supplied from a fixed voltage dc source feeds a fixed resistive-inductive load and a free-wheeling diode. The chopper operates at 1 kHz and 50% duty cycle. Without changing the value of the average dc current through the load, if it is desired to reduce the ripple content of load current, the control action needed will be: (a) increase the chopper frequency keeping its duty cycle constant (b) increase the chopper frequency and duty cycle in equal ratio (c) decrease only the chopper frequency (d) decrease only the duty cycle. 1.24. An inverter capable of supplying a balanced three-phase variable voltage variable frequency output is feeding a three-phase induction motor rated for 50 Hz and 440V. The stator winding resistances of the motor are negligible small. During starting, the current inrush can be avoided without sacrificing the starting torque by suitably applying: (a) low voltage at rated frequency (b) low voltage keeping the V/f ratio constant (c) rated voltage at low frequency (d) rated voltage at rated frequency 1.25 The inverse of the matrix 1 1 0 1 1 1 0 0 1 S - ? ? ? ? = ? ? ? ? ? ? is: (a) 1 0 1 0 0 0 0 1 1 ? ? ? ? ? ? ? ? ? ? (b) 0 1 1 1 1 1 1 0 1 ? ? ? ? - - ? ? ? ? ? ? (c) 2 2 2 2 2 2 0 2 2 - ? ? ? ? - - ? ? ? ? ? ? (d) 1 1 1 2 2 2 1 1 1 2 2 2 0 0 1 - ? ? ? ? ? ? - - ? ? ? ? ? ? ? ? ? ? ? ? 2. This question consists of TWENTY-FIVE statements with blanks. Fill in the blanks with the correct answer. Each statement carries ONE mark. 2.1 Given the matrix 0 1 0 0 0 1 . 6 11 6 A ? ? ? ? = ? ? ? ? - - - ? ? Its eigen values are _______ 2.2. The steady state error due to a step input for type 1 system is _______ 2.3. Closed loop stability implies that ( ) ( ) 1 G s H s ? ? + ? ? has only _______ in the left half of the s-plane.Read More

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