Page 52 - Science and Technology Std 3

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Types of telephones

A telephone is a communication tool that transmits and
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receives sound waves. Telephones allow two or more people to
communicate even though they are far apart. Communication
is done through speaking and writing, when people make
calls or send written messages. There are two main types of

telephones. These are mobile telephones and landlines.

1. Mobile telephones

A mobile telephone is a portable device that transmits and
receives sound waves. The mobile telephone can easily be
carried. The mobile telephone is used to communicate directly
through talking and sending messages.

Figure 3 Communication through a mobile telephone

2. Landline telephones

A landline telephone is usually used in homes and offices. It is
bigger than the mobile telephone. There are two types of landline

telephones. One type is connected using wire and another type is
connected without wire. A landline telephone which is connected
with wire cannot be moved from one place to another. If the
wire is removed, communication is disconnected.

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PROPERTY OF UNITED REPUBLIC OF TANZANIA GOVERNMENT
Ministry of Education, Science and Technology
Science and Technology 3.indd 45 03/08/2019 11:02