The question asks about the starting torque characteristic of a shaded pole motor. To answer this, we need to understand the working principle and typical applications of shaded pole motors.
Correct Option: B) low starting torque
Shaded pole motors are characterized by their simple construction, low cost, and very low starting torque. They are suitable for applications where the load is light and does not require significant torque to start.
The question asks to identify the equipment used in power plants to reduce air pollution caused by smoke. We need to evaluate each option based on its function in a power plant.
Correct Option: D) Electrostatic Precipitators
The question asks to identify which item from the given options is NOT a welding accessory. We need to evaluate each option based on its common use in welding operations.
Based on this evaluation, the vacuum cleaner is the item that is not a direct welding accessory.
B) Vacuum cleaner — A vacuum cleaner is a general cleaning tool and not a specific accessory directly used in the welding process or for welder safety.
The question asks about the primary function of a relay in an electrical system. Understanding the basic operation and purpose of protective relays is key to answering this question.
Correct Option: B) search the fault
The primary function of a protective relay is to detect abnormal operating conditions or faults within an electrical system. Once a fault is detected, it initiates the tripping of a circuit breaker to isolate the faulty section.
To convert a binary number (base 2) to its decimal equivalent (base 10), we use the positional weight method. Each digit in the binary number is multiplied by a power of 2, corresponding to its position, starting from \(2^0\) for the rightmost digit.
Thus, \(100101_2\) is equal to 37 in decimal.
Correct Option: B) 37
A counter has N flip-flops. The total number of states are
A counter is a sequential logic circuit that uses flip-flops to store and count states. Each flip-flop has two stable states (0 or 1). The total number of unique states a counter can represent depends on the number of flip-flops it contains.
Correct Option: D) \(2^N\)
The question asks to identify the majority carriers in the base region of an n-p-n transistor. To answer this, we need to recall the basic structure and doping of an n-p-n transistor.
A) holes. In an n-p-n transistor, the base is a p-type semiconductor, and holes are the majority carriers in p-type materials.
The question asks to identify the electronic component used for generating time-varying waveforms. This implies a device capable of oscillation or switching with a specific timing characteristic. We need to evaluate each option based on its primary function in electronic circuits.
D) UJT (Unijunction Transistor) is specifically designed for switching applications and is widely used in relaxation oscillators to generate various time-varying waveforms such as saw-tooth waves, pulse waves, and square waves. Its negative resistance characteristic is crucial for this function, allowing it to rapidly switch between conducting and non-conducting states based on a capacitor's charge and discharge cycle.
The question asks about the voltage across a Zener diode. To answer this, we need to understand the operating characteristics of a Zener diode, particularly its behavior in forward and reverse bias conditions.
B) is constant in reverse direction
A Zener diode is primarily used for voltage regulation in the reverse breakdown region. In this region, once the Zener voltage (\(V_Z\)) is reached, the voltage across the diode remains remarkably constant, even with significant changes in the current flowing through it. This characteristic is its defining feature and main application.
The question asks to identify the diode type characterized by highly doped p and n regions. We need to recall the construction and doping levels of various diode types to determine the correct answer.
B) Tunnel diode — Tunnel diodes are characterized by very heavily doped p and n regions. This heavy doping results in a very thin depletion region (typically less than \(10^{-6}\) cm), which is essential for the quantum mechanical tunneling effect that gives the diode its unique current-voltage (I-V) characteristic, including a negative differential resistance region.