Question: The percentage 02 by volume in atmosphere air is____________?

• 1. 21%
• 2. 23%
• 3. 77%
• 4. 79%

Question: The percentage O2 by Weight in atmospheric air is____________?

• 1. 18%
• 2. 23%
• 3. 77%
• 4. 79%

Question: The commercial sources of energy are____________?

• 1. solar, wind and biomass
• 2. fossil fuels, hydropower and nuclear energy
• 3. wood, animal wastes and agriculture wastes
• 4. none of the above

Question: Due to which of the following reasons the cables should not be operated too hot ?

• 1. The oil may loose its viscosity and it may start drawing off from higher levels
• 2. Expansion of the oil may cause the sheath to burst
• 3. Unequal expansion may create voids in the insulation which will lead to ionization
• 4. All of the above

Question: The load voltage is approximately constant when a Zener diode is ________________?

• 1. Forward biased
• 2. Unbiased
• 3. Reverse biased
• 4. Operating in the breakdown region

Question: If the load current drawn by unregulated power supply increases, the d.c. output voltage _____________?

• 1. Increases
• 2. Decreases
• 3. Stays the same
• 4. None of the above

Question: If the load current drawn by unregulated power supply increases, the d.c. output voltage______________?

• 1. Increases
• 2. Decreases
• 3. Stays the same
• 4. None of the above

Question: In a loaded Zener regulator, which is the largest Zener current ?

• 1. Series current
• 2. Zener current
• 3. Load current
• 4. None of the above

Question: Which of these is the best description for a Zener diode ?

• 1. It is a diode
• 2. It is a constant current device
• 3. It is a constant-voltage device
• 4. It works in the forward region

Question: If the load resistance decreases in a Zener regulator, then Zener current ______________?

• 1. Decreases
• 2. Stays the same
• 3. Increases
• 4. None of the above