Control System Components Industrial Control Devices: Switches 1.The contact resistance of a manually operated switch is    A. Zero    B. Very high    C. Very low    D. None of the above Answer: Very low   2. Which one of these is not a manually operated switch?    A. Thumbwheel switch    B. Rotary selector switch    C. Crossbar switch    D. Toggle switch Answer: Crossbar switch   3. A switch should have    A. High insulation resistance    B. Low insulation resistance    C. Insulation resistance equal to contact resistance    D. None of the above Answer: High insulation resistance 4. A Thumbwheel switch    A. Has an operating wheel which has numbers on it    B. Is an alternative form of rotary switch    C. Requires half the operating torque required in a rotary switch    D. Supports the features A, B and C Answer: Supports the features A, B and C 5.  When a membrane key switch is pressed    A. The row conductor sheet gets separated from the column contact conductor sheet    B. The ro

  Atomic absorption spectrophotometer 1. Which of the following is the principle of Atomic Absorption Spectroscopy? a) Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states b) Medium absorbs radiation and transmitted radiation is measured c) Colour is measured d) Colour is simply observed Answer: Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states 2. In Atomic Absorption Spectroscopy, which of the following is the generally used radiation source? a) Tungsten lamp b) Xenon mercury arc lamp c) Hydrogen or deuterium discharge lamp d) Hollow cathode lamp Answer: Hollow cathode lamp 3. In Atomic Absorption Spectroscopy, with what material is the cathode in Hollow cathode lamp constructed ? a) Tungsten b) Quartz c) Element to be investigated d) Aluminium Answer: Element to be investigated 4. How can the intensity of radiation be increased in Hollow cathode lamp? a) Addition of non-conductive protective shield of mi

  Instrumental Methods for Chemical Analysis Atomic absorption spectrophotometer 1. Which of the following is the principle of Atomic Absorption Spectroscopy? a) Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states b) Medium absorbs radiation and transmitted radiation is measured c) Colour is measured d) Colour is simply observed Answer: Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states 2. In Atomic Absorption Spectroscopy, which of the following is the generally used radiation source? a) Tungsten lamp b) Xenon mercury arc lamp c) Hydrogen or deuterium discharge lamp d) Hollow cathode lamp Answer: Hollow cathode lamp 3. In Atomic Absorption Spectroscopy, with what material is the cathode in Hollow cathode lamp constructed ? a) Tungsten b) Quartz c) Element to be investigated d) Aluminium Answer: Element to be investigated 4. How can the intensity of radiation be increased in Hollow cathode lamp? a) Additio

  8051 Microcontroller Interview questions Q1. What is 8051 Microcontroller ? The Intel 8051 microcontroller is one of the most popular general-purpose microcontrollers in use today. It is an 8-bit family of microcontroller developed by Intel in the year 1981. This microcontroller was also referred to as “system on a chip” because it has 128 bytes of RAM, 4Kbytes of ROM, 2 Timers, 1 Serial port, and four ports on a single chip. 8051 microcontroller allows CPU to work on 8bits of data at a time.n case the data is larger than 8 bits then it has to be broken into parts so that the CPU can process conveniently. Q2. What are registers in Microcontroller ? Register provides a fast way to collect and store data using microcontrollers and processors.If we want to manipulate data with a controller or processor by performing tasks like addition, subtraction, and so on, we cannot do that directly in the memory, in order to perform these tasks we need registers to process and store the data. Micro

  8051 Microcontrollers Architecture 1. 8051 microcontrollers are manufactured by which of the following companies? a) Atmel b) Philips c) Intel d) All of the mentioned Answer: All of the mentioned 2. AT89C2051 has RAM of: a) 128 bytes b) 256 bytes c) 64 bytes d) 512 bytes Answer: 128 bytes 3. 8051 series has how many 16 bit registers? a) 2 b) 3 c) 1 d) 0 Answer: 2 4. When 8051 wakes up then 0x00 is loaded to which register? a) PSW b) SP c) PC d) None of the mentioned Answer: PC 5. When the microcontroller executes some arithmetic operations, then the flag bits of which register are affected? a) PSW b) SP c) DPTR d) PC Answer: PSW 6. How are the status of the carry, auxiliary carry and parity flag affected if the write instruction MOV A,#9C ADD A,#64H a) CY=0,AC=0,P=0 b) CY=1,AC=1,P=0 c) CY=0,AC=1,P=0 d) CY=1,AC=1,P=1 Answer: CY=1,AC=1,P=0 7. How are the bits of the register PSW affected if we select Bank2 of 8051? a) PSW.5=0 and PSW.4=1 b) PSW.2=0 and PSW.3=1 c) PSW.3=1 and PSW.4=1 d)