Class 10 Science Lesson 13

Exercise

1. Choose the correct option for the following questions.

(a) Which of the following represents an analogue signal?

(i) infrared ray thermometer
(ii) computer
(iii) smartwatch
(iv) medium wave radio

Answer: (iv) medium wave radio

(b) …… indicates 1 byte memory.

(i) 0000
(iii) 100000
(ii) 00000000
(iv) 000001

Answer: (ii) 00000000

(c) Which one of the following is the group of variables in the correct order among the steps of digital signal transmission?

(i) source, input transducer, decoder, modulator, channel, demodulator, encoder, output transducer
(ii) source, input transducer, encoder, demodulator, channel, modulator decoder, output transducer
(iii) source, input transducer, encoder, modulator, channel, demodulator decoder, output transducer
(iv) source, encoder, input transducer, modulator, channel, decoder, demodulator, input transducer

Answer: (iii) source, input transducer, encoder, modulator, channel, demodulator decoder, output transducer

(d) Which of the following is an audio file format?

(i) SVI
(iii) MP3
(ii) MP4
(iv) 3GP

Answer: (iii) MP3

(e) What does the behavior of posting information about new scientific discoveries from time to time on social networks indicate?

(i) unsystematic use of social networks
(ii) digital well-being skills
(iii) awareness of digital wellbeing
(iv) digital reputation management

Answer: (iv) digital reputation management

2. Differentiate between:

(a) Analogue Signals and Digital Signals

(b) Analogue Signal Transmission and Digital Signal Transmission

(c) Digital Integrity and Digital Reputation

3. Answer the following questions:

(a) Define the bit and byte used in computer memory.

Answer: A bit (binary digit) is the smallest unit of data, representing either 0 or 1. A byte consists of 8 bits and is used to store characters like letters or symbols in computer memory.

(b) Present the currently used high-speed internet as a Broadband transmission.

Answer: Broadband is high-speed internet that is always on. It uses technologies such as DSL, cable modem, fiber optics, and satellite to provide fast data transfer and supports applications like video calls, streaming, and gaming.

(c) Write four advantages of digital transmission.

Answer:

1. High-speed data transmission
2. Lower noise and error rates
3. Easier to encrypt and secure
4. Supports data compression and multiplexing

(d) Explain the impact of digital technology on the development of information and communication.

Answer:

• Email vs Postal Mail: Instant communication via email replaces slow postal systems.
• Cloud Storage: Tools like Google Drive offer access and sharing of data from anywhere, promoting collaboration.

(e) Present any four examples of digital technology used in daily life.

Answer:

1. Mobile phones
2. Online banking
3. E-learning platforms (e.g., Google Classroom)
4. Smart appliances (e.g., digital TVs, smart fridges)

(f) Write two positive and negative effects of digital technology in daily life.

Answer:

Positive:

• Easier access to information
• Improved communication

Negative:

• Social isolation
• Screen addiction

(g) Define digital citizenship.

Answer: Digital citizenship is responsible and ethical use of technology to engage in society. A good digital citizen respects others, protects privacy, and promotes positive online interactions.

(h) Write four characteristics of a good netizen.

Answer:

1. Uses respectful language online
2. Avoids spreading false information
3. Reports harmful behavior
4. Protects privacy

(i) What is online reputation? Write with examples.

Answer: Online reputation is how people perceive you based on your digital presence.
Example: A student with a helpful blog is seen as knowledgeable; offensive posts can harm reputation.

(j) What is digital well-being?

Answer: Digital well-being is maintaining a healthy balance in using digital tools, such as managing screen time and avoiding tech-related stress.

(k) Write the advantages of digital well-being.

Answer:

1. Reduces stress and burnout
2. Improves focus
3. Supports better sleep and health
4. Encourages mindful tech use

Precautions for digital well-being:

1. Set screen time limits
2. Take device breaks
3. Use focus modes
4. Practice safe digital habits

(l) What is digital reputation management?

Answer: It involves monitoring and improving your online image, such as deleting harmful posts and maintaining a professional profile.

(m) Give two examples of digital reputation management.

Answer:

1. Updating LinkedIn with skills
2. Removing inappropriate content from social media

(n) Mention four importance of digital reputation management.

Answer:

1. Builds employer trust
2. Enhances credibility
3. Prevents online conflicts
4. Maintains a positive online image

(o) Write two positive effects based on the use and utility of social media.

Answer:

1. Connects people globally
2. Encourages learning and creativity

(p) Write two possible negative effects of using social media.

Answer:

1. Promotes unrealistic comparisons
2. Can cause addiction and misinformation

(q) Write your plan to make a 5-minute audio-visual material covering the topics included in any one unit under the science and technology of class 10. What can be done to make that audio-visual material of 3 minutes? Write, including, the necessary steps.

Answer:

Plan: Topic – Environment Conservation (Science)

Steps:

1. Research environmental problems and solutions
2. Write script with key messages
3. Collect visuals (photos, clips, charts)
4. Record voice narration
5. Edit with music, captions, transitions

To shorten to 3 minutes:

• Focus only on main issues like pollution or deforestation
• Use concise visuals
• Trim repetitive audio, keep only essential content