Do you violate the provisions of traffic law, if, while driving a car, you talk on a phone by holding the phone in your hand?

Yes, this is a violation of the regulations. According to Art. 45 para. 2 pt. 1 of the Road Traffic Act, a driver is prohibited from using a phone while driving if it requires holding the handset or microphone. Such an action distracts the driver's attention and limits their ability to operate the steering wheel correctly. However, using a hands-free kit is permitted.