Question & Answers

1. What is the principle of an alternator? The alternator works on the principle on the Faraday’s law of electromagnetic induction. Whenever a conductor links with a magnetic field, either the conductor is moving, or the field is moving, an emf is induced in the conductor. 2. What are the different types of alternators? Which

1. What are the advantages of three-phase induction motor? Simple construction High reliability Rugged construction High efficiency Low cost Less maintenance Self starting torque Good power factor. 2. What are the disadvantages of three phase induction motor? The speed is not constant with load. Reduction in efficiency when speed is varied. Low starting torque compared

1. Define a transformer. A transformer is a static device which change the alternating voltage form one level to another. 2. What is staggering in the construction of transformers? In transformer, the joints in the alternate layers are staggered in order to avoid the presence of narrow gaps right through the cross section of the

1. What is an electric motor? Electric motor is a machine which converts electrical energy into mechanical energy. 2. Define DC motor. DC motor converts d.c electrical input into mechanical output. 3. What is the basic principle of operation of a dc motor? The basic principle of operation of a dc motor is that, a

1. What is an electrical generator? An electrical generator is a machine which converts mechanical energy to electrical energy. 2. What is the basic principle of a dc generator? Basic principle of a dc generator is Faraday’s law of electromagnetic induction. whenever a conductor is moved in a magnetic field, dynamically induced emf is produced

1. What are the advantages of micro controller over microprocessor? The overall system cost is low, as the peripherals are integrated in a single chip. The size is very small. The system is easy to troubleshoot and maintain. If required additional RAM, ROM and I/O ports may be interfaced. The system is more reliable. 2.

1. What is meant by DMA data transfer? DMA stands for Direct Memory Access. In order to transfer bulk amount of data between memory and I/O device without the involvement of CPU, this technique is used. 2. What are the modes of operations supported by 8255? Simple  mode Strobed I/O mode Bidirectional mode 3. What is

1. What are the three basic multiprocessor configurations that the 8086 can support? Coprocessor Configuration Closely Coupled Configuration Loosely Coupled Configuration 2. What do you mean by numeric processor? 8087 is the numeric processor or numeric co-processor. It adds arithmetic, trignometric, exponential and logarithmic instructions to 8086/8088 instruction set for all data types. It supports

1. What do you mean by non maskable interrupt? Non-maskable interrupt (NMI) is the highest priority hardware interrupt that triggers on the positive edge. This interrupt cannot be disabled or masked. It is used to save program data or processor status in case of system power failure. 2. List out the segment registers of 8086?

1. How many machines cycles and T-states are needed to execute STA 4200H in 8085 processor? To execute STA 4200H instruction, 4 machine cycles and 13 T-states are needed. Machine Cycles         T-states Opcode fetch                4 Memory Read               3 Memory