This question asks for the specific term that describes the difference between the synchronous speed and the actual operating speed of an electric motor, particularly an induction motor. Understanding the fundamental concepts of motor operation is key to answering this.
Correct Option: C) slip
Slip is defined as the relative speed between the rotating magnetic field (synchronous speed) and the rotor speed. It is usually expressed as a fraction or percentage of the synchronous speed:
\[ s = \frac{N_s - N}{N_s} \]where \(s\) is slip, \(N_s\) is synchronous speed, and \(N\) is actual rotor speed.
The question asks to identify which of the given motor types is self-starting. This requires understanding the operating principles of each motor, particularly how they generate a starting torque.
B) Shaded pole motor — Shaded pole motors are single-phase induction motors that are inherently self-starting. They achieve this by using a shading coil (a short-circuited copper ring) on a portion of each pole. This coil causes a phase lag in the magnetic flux in the shaded part, creating a sweeping or shifting magnetic field across the pole face. This shifting field induces a starting torque in the rotor, allowing the motor to start rotating without any auxiliary winding, capacitor, or switch.
The question asks about the device used to relieve water hammer pressure in hydroelectric power plants. Water hammer is a phenomenon caused by sudden changes in water flow, leading to pressure surges. We need to identify the component specifically designed to mitigate this.
Correct Option: D) surge tank
The question asks for the full form of the acronym TIG Welding. This is a direct recall question related to common welding processes. Understanding the components of the acronym is key.
Correct Option: B) Tungsten Inert Gas Welding
This option correctly identifies the components of the TIG welding acronym. Tungsten is the material of the non-consumable electrode, and an inert gas (like argon or helium) is used for shielding to prevent oxidation and contamination of the weld puddle.
The question asks about the type of modulation used for transmitting the picture signal in a Television (T.V.) system. Understanding the characteristics of different modulation techniques and their suitability for video transmission is key.
A) amplitude modulation — T.V. picture transmission uses Amplitude Modulation (specifically Vestigial Sideband Amplitude Modulation or VSB-AM) because the video signal's amplitude variations directly correspond to the brightness levels of the picture. AM effectively translates these amplitude variations onto the carrier wave.
The question asks about the process of extracting the original signal from a modulated wave. This is a fundamental concept in communication systems, where a high-frequency carrier wave is modified (modulated) to carry information, and then the information needs to be recovered at the receiver end.
B) detection. Detection is the process of extracting the original modulating signal (information) from the modulated carrier wave. It is also commonly referred to as demodulation.
This question tests the basic understanding of an OR gate's functionality. An OR gate is a fundamental digital logic gate that produces a high output if at least one of its inputs is high. Otherwise, its output is low.
A) is high. As established, an OR gate outputs high if any of its inputs are high. Since one input is high, the output will be high.
To convert a decimal number to hexadecimal, we use the division-remainder method. We repeatedly divide the decimal number by 16 (the base of hexadecimal) and record the remainders. The hexadecimal equivalent is formed by reading the remainders from bottom to top, converting any remainders greater than 9 to their corresponding hexadecimal letters (A for 10, B for 11, C for 12, D for 13, E for 14, F for 15).
Divide 43 by 16.
\[ 43 \div 16 \]The quotient is 2, and the remainder is 11.
\[ 43 = 16 \times 2 + 11 \]The remainder is 11. In hexadecimal, 11 is represented by the letter 'B'.
Now, divide the quotient (2) by 16.
\[ 2 \div 16 \]The quotient is 0, and the remainder is 2.
\[ 2 = 16 \times 0 + 2 \]The remainder is 2. In hexadecimal, 2 is simply '2'.
The remainders are 2 and B. Reading them from bottom to top gives 2B.
Therefore, decimal 43 in hexadecimal is 2B.
A) 2B is correct because, through the division-remainder method, 43 divided by 16 gives a quotient of 2 and a remainder of 11 (which is 'B' in hexadecimal). Then, 2 divided by 16 gives a quotient of 0 and a remainder of 2. Reading the remainders from bottom to top (2 then B) yields 2B.
The question asks to identify the nature of a JFET (Junction Field-Effect Transistor). We need to understand how a JFET operates and what controls its current flow.
C) a voltage controlled device. The JFET's drain current is controlled by the voltage applied between the gate and source terminals. A change in gate-source voltage \((V_{GS})\) leads to a change in the width of the depletion region, which in turn modulates the channel resistance and thus the drain current \((I_D)\).
The question asks about the type of gain achieved using a Common Base (CB) configuration for a transistor. We need to recall the characteristics of the CB configuration, particularly its current, voltage, and power gain properties.
Considering the primary characteristic, the CB configuration is known for its excellent voltage amplification capabilities, despite having a current gain less than unity.
Correct Option: B) The Common Base (CB) configuration is primarily known for providing significant voltage gain. While it has a current gain less than 1, its low input impedance and high output impedance allow for substantial voltage amplification.