Two concentric spherical shells at radii r = c and r = d have potentials V_1 and V_2. What is the potential V(r) in the region c < r < d?
Signals and Systems
4 Questions
GATE→2022→Signals and Systems→Continuous/Discrete Signals & Transforms
Q29
MCQ[2 Marks]
For a causal LTI system governed by y(t) + 0.25 (dy/dt) = 2 x(t), find its impulse response h(t).
GATE→2022→Signals and Systems→Continuous/Discrete Signals & Transforms
Q30
MCQ[2 Marks]
An input x(t) is passed through an LTI bandpass filter with impulse response h(t). What is the system output?
GATE→2022→Signals and Systems→Continuous/Discrete Signals & Transforms
Q31
MCQ[2 Marks]
For the continuous-time system defined by y(t) = x(e^t), the system is
GATE→2022→Signals and Systems→Continuous/Discrete Signals & Transforms
Q32
MCQ[2 Marks]
A periodic signal x[n] with period N=3 has non-zero Fourier coefficients a_{-3} = 2 and a_4 = 1. Which option represents the signal?
Electrical Machines
6 Questions
GATE→2022→Electrical Machines→DC & AC Machines
Q33
MCQ[1 Mark]
Which single-phase induction motor type has the highest power factor during steady-state running conditions?
GATE→2022→Electrical Machines→DC & AC Machines
Q34
NAT[1 Mark]
A 3-phase 8-pole induction motor has stator frequency 40 Hz and rotor frequency 1 Hz. Find motor speed in rpm.
GATE→2022→Electrical Machines→DC & AC Machines
Q35
NAT[2 Marks]
A separately excited DC motor with R_a = 1 Ω draws 30 A at 1000 RPM (V = 280 V) driving a torque proportional to speed load. Find the speed in RPM if an extra 10 Ω is added in series with armature.
GATE→2022→Electrical Machines→DC & AC Machines
Q36
NAT[2 Marks]
A 4-pole induction motor with J = 0.1 kg-m^2 drives a constant load torque T_L = 2 Nm. Speed increases linearly from 1000 to 1500 RPM in 4 s. Find energy consumed in Joules.
GATE→2022→Electrical Machines→DC & AC Machines
Q37
NAT[2 Marks]
A star-connected synchronous motor (400 V, 50 kVA, X_s = 1 Ω) has shaft load 10 kW, 2 kW losses, 0.8 leading p.f. Find per-phase excitation emf E_f in volts.
GATE→2022→Electrical Machines→DC & AC Machines
Q38
NAT[2 Marks]
An induction motor draws 5x starting current. To reduce starting current to 2x using a 3-phase autotransformer, find the transformation ratio x (or tapping percentage).
An ideal full-bridge single-phase inverter with 1000 V DC bus feeds load current i(t) = 10 sin(wt - pi/3) A with square-wave voltage (50% duty cycle). Find active power in watts.
For the ideal single-phase bridge rectifier with I_dc = 15 A and firing angle alpha = 45°, find the amplitude of the fundamental source current component in amperes.
For a DC-DC buck-boost converter with inductor current waveform (min 12 A, max 16 A over t_on = 20 us, t_off = 30 us) and output voltage ripple 1 V, find the output capacitance in µF.