Test: Transients - Electronics and Communication Engineering (ECE) MCQ

Answer: a
Explanation: The resonant circuit refers to the tank circuit. It is parallel combination of an inductor and a capacitor.

Answer: b
Explanation: A waveguide mode with a guided termination is represented by TEmnp and TMmnp. Here m and n are the orders of the waveguide and p is the order of the resonant cavity. It is always a non-zero value.

Answer: a
Explanation: The cut off frequency of the waveguide of dimensions a x b with the resonant cavity of dimension d is given by fc = √((m/a)² + (n/b)² + (p/d)²)/2. Here m and n are the orders of the waveguide, p is the order of the cavity and v is the velocity

Answer: a
Explanation: The power of a line is given by P = I²R. On substituting for I = 5 and R = 120, we get P = 5² x 120 = 3000 units.

Answer: a
Explanation: The power of a wave is given by P = 0.5 η H², where η is the intrinsic impedance and H is the magnetic field intensity. On substituting for η = 377 and H = 2.5, we get P = 0.5 x 377 x 2.5² = 1.17 kilo watts.

Answer: a
Explanation: The power of a wave is given by P = 0.5 E²/η, where E is the electric field intensity and η is the intrinsic impedance. On substituting for E = 12.8 and η = 377, we get P = 0.5 x 12.8²/377 = 0.217 units.

Answer: c
Explanation: The form and the mode of propagation of the wave in a waveguide is determined by the type and location of the excitation device.

Answer: a
Explanation: Using a guided termination, the guides serves as a reflector. If the distance between the exciter and the wall is properly adjusted, the transmitted and the reflected wave will be in phase.

Answer: d
Explanation: The waveguide is usually excited by the antenna rod. The reflection depends on the phase of excitation and the antenna current

Answer: b
Explanation: A waveguide passes only high frequency waves (in GHz range) and attenuates low frequencies. This is the characteristic of a high pass filter.