Aricent Technologies Technical Interviews Question Bank continued from Part 1
Q-6. What are active and passive components? Give examples of both.
A : Active components are components that produce energy (in the form of voltage or current) such as transistors, while passive components consume energy like resistor, capacitor etc.
Q-7. Why is input resistance of an operational amplifier high and output resistance low?
A : Input resistance of an op-amp is kept high for efficient loading at input and maximum transfer of input to the output end (and output end to load) because op-amp acts as an current exchange device from input to output.
Q-8. What is GSM?
A : GSM, which stands for Global System for Mobile communication, is a second generation (2G) cellular standard under ETSI (European Telecommunication Standards Institute) developed to cater voice services and data delivery using digital modulation. Earlier called Group Speciale Mobile, it was founded in 1982 to replace the incompatible analog (1G) system.
Q-9. What is CDMA?
A : Code Division Multiple Access, briefly known as CDMA, is a channel access technique used for radio/wireless communication between the Mobile Station and Base Station. It uses different orthogonal codes for different users to allow multiple users to be multiplexed over the same physical channel simultaneously.
Q-10. What is the main difference between GSM and CDMA?
A : The main difference between the two is the multiplexing technique they use for the wireless communication between the Mobile Station and Base Station. CDMA uses different orthogonal (i.e. non-overlapping) codes for multiple users such that any number of users can communicate with each other without any interference by others (due to orthogonality). On the other hand, GSM uses narrowband TDMA as the channel access scheme in which multiple users are assigned different time slots in which they can use the entire bandwidth available. It can allow eight calls on the same frequency simultaneously.
Gautam Vashisht, JIIT Noida
Continued to Part 3