| 1. | A rectangular metal waveguide filled with a dielectric material of relative permittivity Er= 4 has the inside dimensions 3.3 cm x 1.2 cm. The cut-off frequency for the dominant mode is ? | |
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12.5 GHz
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2.5 GHz
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10.0 GHz
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5.0 GHz
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Report Question| 2. | The amounts of time-average energies stored in electric and magnetic field for p-th mode of a cavity resonator will be ? | |
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equal in the case of spherical cavities
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always equal
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equal in the case of fundamental mode of oscillation
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equal provided the Q-factor is very high
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| 3. | The correct statement is ? | |
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Microstrip lines cannot support pure TEM mode of propagation but shielded coaxial lines can
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Microstrip lines can support pure TEM mode of propagation but shielded coaxial lines cannot
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Neither microstrip lines nor shielded coaxial lines can support pure TEM mode of propagation
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Both microstrip lines and shielded coaxial lines can support pure TEM mode of propagation
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| 4. | In a waveguide network, there is a component which consists of an E-plane Tee combined with an H-plane Tee. What is this component generally-known as ? | |
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Magic Tee
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Directional Tee
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Coupler Tee
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Phased array Tee
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| 5. | A higher directivity is specified by ? | |
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low gain low bandwidth
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high gain high bandwidth
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low gain high bandwidth
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high gain low bandwidth
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| 6. | By measuring the VSWR values in the main and ancillary waveguides of a directional coupler, we can determine its ? | |
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phase co-relation and efficiency
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attenuation and radiation efficiency
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directivity and coupling factor
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frequency shift and phase variations
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| 7. | Electromagnetic oscillations are sustained in a two-cavity klystron due to ? | |
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feedback of output power to the input cavity with phase difference of 180°
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feedback of output power to the input cavity in proper phase
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feedback of power from thermal noise of load circuit with phase lag of 90°
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feedback of power from external load to input cavity in proper phase
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| 8. | To overcome difficulties with strapping at high frequencies, the type of cavity structure desired for magnetron is ? | |
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slot
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hole and slot
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rising sun
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vane
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| 9. | The slow-wave structure of a TWT is provided with an attenuator, Which one of the following is the function of such an attenuator ? | |
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It is used to broadband the device
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It prevents the RF power from reaching the output of the device when the beam is switched on
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It prevents oscillations in the device
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It reduces the noise level of the device
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| 10. | For using as a local oscillator for frequency measurements, the most suitable microwave source would be ? | |
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reflex klystron
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travelling wave tube
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magnetron
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double cavity klystron
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