Technical MCQs

1. From the following, which is not a four layer diode? (A) Diac (B) Thyristor (C) Triac (D) SCR 2. Basically a Triac is like a: (A) NPN transistor (B) PNP transistor (C) Unidirectional SCR (D) Bidirectional SCR 3. from the following, which is a bidirectional device but without a gate: (A) Diac (B) SCR (C) Triac (D) None of the above 4. Which device has an emitter and two connections to the base without a collector terminal? (A) Diac (B) SCR (C) UJT (D) Triac 5. Generally a UJT is not used as a: (A) Timing device (B) Transistor amplifier (C) Switching device (D) All of the above 6. Which device has negative resistance? (A) Tunnel diode (B) Gas diode (C) Vacuum diode (D) None of the above 7. Basically a tunnel diode is used for: (A) HF (B) Microwave frequencies (C) Very low frequencies (D) 60 Hz 8. Which uses two junctions of opposite polarities? (A) Varistor (B) Tunnel diode (C) Zener diode (D) None of the above 9. from the following in which reverse voltage is used: (A) Varactor (B) L

1. Basically a unipole antenna is known as: (A) Line radiator (B) Omnidirectional radiator (C) Unidirectional radiator (D) None of the above 2. We can increase front to back ratio by: (A) Using materials of high conductivity (B) Sacrificing gain (C) Using materials of high conductivity (D) All of the above 3. The lower value of Q in case of antenna indicates: (A) Higher distortion (B) Lower distortion (C) Higher bandwidth (D) Lower bandwidth 4. An antenna is basically synonymous to a: (A) Regulator (B) Reflector (C) Transformer (D) Generator 5. Log periodic antenna is basically a: (A) Directional antenna (B) Frequency independent antenna (C) Frequency dependent antenna (D) None of the above 6. An isotropic antenna has the gain: (A) 5 db (B)  10 db (C) 7 db (D) 3 db 7. The loop antenna has the radiation pattern in the form of: (A) Circle (B) Cardiod (C) Semi-circle (D) None of the above 8. An antenna is basically: (A) Capacitive (B) Resistive above its resonance frequency (C) Inductive

1. From the following, which material has highest coercive force (A/m)? (A) Cobalt steel (B) Alcomax (C) Tungsten steel (D) Carbon steel 2. From the following, which material has least value of remenance in Wb/m 2 ? (A) Cobalt steel (B) Alini (C) Alcomax (D) Tungsten steel 3. Basically Manganin is an alloy of: (A) Copper, chromium and cadmium (B) Copper, aluminum and chromium (C) Copper, zinc and lead (D) Copper, manganese and nickel 4. Basically constantan is an alloy of: (A) Lead and zinc (B) Aluminum and copper (C) Nickel And copper (D) Nickel and silver 5. Constantan has the major application in: (A) Transistors (B) Heat elements for valves (C) Thermocouples (D)  Precision resistance 6. Generally the transistor voltmeter is: (A) Moving coil instrument (B) Dynamometer type instrument (C) Moving iron instruments (D) None of the above 7. Which is not the advantage of a semi-conductor strain gauge? (A) Linearity over wide range   (B) High fatigue life (C) Low hysteresis effect (D) High