NCERT Solutions: My Brother's Great Invention

Table of Contents
1. Let us do these activities before we read (Page 92)
2. Let us discuss (Page 94)
3. Let us discuss (Page 98)
4. Let us think and reflect (Page 99)
5. Let us learn (Page 101)
6. Let us listen (Page 105)
7. Let us speak (Page 105)
8. Let us write (Page 106)
9. Let us explore (Page 107)
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Let us do these activities before we read (Page 92)

QI. Guess the invention: 

1: I am a concept invented by ancient Indian mathematicians. I add value to numbers. Without me, calculations in the modern digital world would be impossible. Who am I?
Ans: Zero

2: I am an ancient Indian practice, now popular globally. I focus on physical and mental well-being. What am I?
Ans: Yoga

QII: Discuss in groups of four what you think the world today would be like without inventions and discoveries.
Ans: Without inventions and discoveries, life would be very different and much harder. There would be no electricity, so homes and hospitals would rely on natural light and simple medicines. 

• Communication would be slow - people would depend on letters or messengers instead of phones and the internet. 
• Transport would be limited to walking, animals or basic carts, so travelling long distances would be rare. 
• Everyday tasks that machines do now would take much longer, and many modern jobs and comforts would not exist. Communities would depend more on local skills and natural resources.

QIII: Fill the grid given below with missing letters to complete the words. These words display qualities of an inventor.

Ans: 

Let us discuss (Page 94)

QI: Complete the cause-and-effect table given below.

Ans: 

QII: Do you think Anand was able to keep his promise regarding the time machine? If yes, why? If no, why not?
Ans: No. It is unlikely that Anand kept his promise. He was excited about his invention and upset when his parents did not believe him. The text suggests he might act on his own when upset so that he could have tried the time machine in private. 
His behaviour - tinkering when alone and often not being believed - supports the idea that he tested the machine without telling his parents.

Let us discuss (Page 98)

Q: Arrange the following events in the correct order of occurrence.

1. The door swings open, and they see Boppa, standing there with an evil grin.
2. Boppa is nowhere to be found, but his green scarf is lying near the time machine.
3. Mrs. Sharma, her husband, and Dr. Mohan unlock the door and enter the house to help the children.
4. Anita wakes Anand up, informing him that someone is trying to get into the house.
5. Anand misleads Boppa into entering his room instead of his father's room.

Ans: 4 → 1 → 5 → 3 → 2

1. Anita wakes Anand up, informing him that someone is trying to get into the house.
2. The door swings open, and they see Boppa, standing there with an evil grin.
3. Anand misleads Boppa into entering his room instead of his father's room.
4. Mrs. Sharma, her husband, and Dr. Mohan unlock the door and enter the house to help the children.
5. Boppa is nowhere to be found, but his green scarf is lying near the time machine.
Explanation: First, Anita wakes Anand because she notices someone at the door. The door then opens, revealing Boppa. Anand quickly tricks Boppa into the wrong room to delay him. Neighbours enter to help, and finally, Boppa has already disappeared, leaving only his scarf by the time machine.

Let us think and reflect (Page 99)

QI. Read the extracts given below and answer the questions that follow.

1. Before beginning, let me put you in the picture. I am Anita, fourteen years old. My brother Anand, one year younger than me, caused all that hoo-ha with his burglar alarm. The trouble with him is that he thinks he is a scientist. He loves tinkering with all sorts of electrical gadgets, tools, dynamos, planks of wood, and things like that. And he keeps creating 'inventions' that never work out as they are supposed to.

(i): Complete the following sentence suitably by choosing the correct option from those given in the brackets.

When Anita says, "...let me put you in the picture", she wants to __________ (introduce/summarise) the situation for the benefit of the readers.
Ans: introduce
Explanation: Anita wants to give background information so that readers understand the situation and characters before the events begin.

(ii): Anand loves 'tinkering' with all sorts of electrical gadgets. This means that he enjoys ______ gadgets.
A. dismantling and creating 
B. labelling or naming
C. repairing or improving 
D. collecting and displaying
Ans: A
Explanation: 'Tinkering' means taking things apart and putting them together again, experimenting and creating new things, which matches option A.

(iii): Which of the following options most suitably describes Anand's personality?
A. methodical and cautious 
B. creative and experimental
C. energetic and hasty 
D. shy and reserved
Ans: B
Explanation: Anand tries new gadgets and inventions and experiments with ideas, so he is creative and experimental rather than cautious or shy.

(iv): Based on the extract, compare what Anita thinks of her brother Anand with what he thinks of himself.
Ans: Anita thinks Anand's inventions cause trouble and often do not work as intended, so she finds him more of a nuisance. Anand, however, believes he is a scientist and takes pride in his experiments and inventions.

2. I was about to direct him upstairs when Anand said quickly, "The one next to this one." 
"You silly goose!" I said angrily as soon as the man had gone. "That's your room. He'll come back as mad as mad can be." 
"At least it will give us some time to think of something," Anand said. "He'll take a while to locate the light switch. Let's shout."All of a sudden there was a crash followed by a loud scream. More strange noises emerged from the next room-a few muffled thumps, an eerie whine, and a low, humming sound.

(i): Anita was angry with Anand because __________
Ans: he misdirected the intruder into Anand's own room, which could make the intruder more likely to become aggressive and cause harm.

(ii): Which action of Anand shows his presence of mind?
Ans: Anand quickly led the intruder to his room instead of his father's, buying time and giving the family a chance to prepare or call for help.

(iii): What might be the cause of the strange noises emerging from the next room?
A. The intruder moving furniture around
B. Anand's time machine getting activated
C. The intruder located the light switch
D. Anand's invention malfunctioning
Ans: B
Explanation: The extract mentions an eerie whine and humming sound, which suggests a machine starting; within the context, this fits Anand's time machine activating.

(iv): Which of the following best describes the atmosphere in this extract?
A. relaxing B. peaceful C. tense D. sad E. suspenseful F. joyful
(a) A, D and E 
(b) B and F 
(c) C and E 
(d) Only D
Ans: (c) C and E
Explanation: The scene is both tense and suspenseful because of the intruder, shouting and strange machine noises that make the situation uncertain and frightening.

QII: Complete the table with the suitable traits of the characters based on evidence from the extract.

Ans:

QIII. Answer the following questions.

1: What prompted Anand to create the burglar alarm?
Ans: A series of thefts in the neighbourhood prompted Anand to design the burglar alarm to help protect the houses.

2: How did Anand's father become the target of the burglar alarm?
Ans: The alarm was set to trigger on any soft opening of the door. Papa opened the door quietly, which activated the alarm-specifically the water-bag mechanism-and so he became the unintended target.

3: How did Anand's parents and sister react to his ideas?
Ans:

• Parents: They were sceptical and worried. They did not fully trust the practicality of his devices and often thought his inventions were unrealistic or likely to cause trouble.
• Sister: Anita was sceptical and cautious about Anand's ideas. She doubted whether his inventions would work, warned him not to involve her, and asked practical questions about how the burglar alarm functioned.

4: How did Anand behave when he was on his 'inventing binges'?

Ans: Anand became untidy and absorbed in his work. He would not comb his hair, made loud noises with hammering and sawing, and took apart gadgets to reuse their parts for new inventions.

5: Why did Mr. Sharma not believe Anand when he spoke about his time machine?
Ans: Mr. Sharma found the idea of a working time machine unbelievable and therefore thought Anand was imagining things rather than telling the truth.

6: Give an ending to this story, explaining what might have happened to Boppa.
Ans: Boppa may have been frightened by the noises and lights coming from the time machine, and ran away in panic, dropping his scarf. He likely left before the neighbours arrived, which explains why he could not be found later. Another possibility is that some noise made him hide nearby and later escape quietly.

Let us learn (Page 101)

I. Read the highlighted word in the following sentence. 

It's quite simple. The moment the door opens, this alarm is tripped off and makes a clanging sound. 

Such sound words are called onomatopoeic words.

Onomatopoeia is the use of words that imitate actual sounds of the thing they describe. The 'boom' of a firework exploding, the 'ding-dong' of a bell, the 'pitter-patter' of rain drops, the 'tick-tock' of a clock are all examples of onomatopoeia.

1: Read the sound words used in the extract in Column 1. Complete Column 2 by matching expressions from the box given below. An example has been done for you.

Ans:

II. Read the highlighted phrase in the following sentence from the extract. 

Well, that was the end of peace and quiet in the house. 

The highlighted phrase displays a combination of two words generally used together in a fixed order. Such phrases are called binomials.

Binomials are expressions consisting of two words, usually linked by a conjunction such as 'and' or 'or', that are commonly used together in a fixed order. The two words convey a single meaning or an opposite.

1: Match the words in Column 1 with the correct pairs in Column 2 to make binomials.

Ans: 

2: Complete the following sentences with suitable binomials from 1.

(i) This project will be a ______________ moment for our team's success.
(ii) After a long journey, we were relieved to arrive home______________.
(iii) Every friendship works well when there is a balance of______________.
(iv) She organised all the ______________ in the cupboard, to make space for new clothes.
(v) Before making a decision, it is important to weigh the______________ carefully.
(vi) This is our final chance to perform on stage, it is ______________.

Ans:

 (i) This project will be a make-or-break moment for our team's success.
(ii) After a long journey, we were relieved to arrive home safe and sound.
(iii) Every friendship works well when there is a balance of give and take.
(iv) She organised all the odds and ends in the cupboard, to make space for new clothes.
(v) Before making a decision, it is important to weigh the pros and cons carefully.
(vi) This is our final chance to perform on stage, it is now or never.

3: Complete the paragraph by using the phrasal verbs given in the box below.

It had been raining and we (i) ___________ time to set up for the function, so we quickly (ii) ___________ some decorations using whatever materials we had. We accidentally (iii) ___________ the fire alarm because of the smoke from the bonfire. Thankfully, the rain(iv) ___________ just as the guests were arriving, and despite all the chaos, the function (v) ___________ to be a huge success.

Ans: It had been raining and we (i) ran out of time to set up for the function, so we quickly (ii) rigged up some decorations using whatever materials we had. We accidentally (iii) tripped off the fire alarm because of the smoke from the bonfire. Thankfully, the rain (iv)  let up just as the guests were arriving, and despite all the chaos, the function (v) turned out to be a huge success.

QIII: Read the highlighted expressions in the following sentence from the extract.

And this is not the first time he's got on Papa's nerves or frightened someone half to death in the house. 

The highlighted expressions are called idioms.

Complete the following sentences by filling in the blanks with suitable idioms from the text given in the box below.

1. Shekhar knew he would _______________________ for breaking his mother's favourite flower vase.
2. We _______________________ trying to help the injured dog and get it to the vet as quickly as possible.
3. Faizy distracted Kanchan, _______________________ for us to get inside the room to prepare the birthday surprise.
4. The constant power fluctuations during meetings can_______________________.
5. When I am alone at home, any unexpected loud noise in the night can _______________________.
Ans: 1. Shekhar knew he would get a shelling for breaking his mother's favourite flower vase.
2. We fell over ourselves trying to help the injured dog and get it to the vet as quickly as possible.
3. Faizy distracted Kanchan, leaving the coast clear for us to get inside the room to prepare the birthday surprise.
4. The constant power fluctuations during meetings can get on our nerves.
5. When I am alone at home, any unexpected loud noise in the night can frighten me half to death.

QIV. Read the highlighted words in the given sentence. 

It was indeed the fellow who had recently begun sweeping out the compounds in our row of houses. 

Here we refer to two completed actions─the recent past (new action) and the later past (old action).

1: Underline the verbs in simple past and past perfect tense for the following sentences from the extract.

(i) Ma had rushed in to see what the racket was all about and found Papa standing there, sopping wet and scowling.
(ii) Anand had vanished by this time and reappeared only after dinner when Papa had cooled down.

Ans: (i) Ma had rushed in to see what the racket was all about and found Papa standing there, sopping wet and scowling.
(ii) Anand had vanished by this time and reappeared only after dinner when Papa had cooled down.

2: Fill in the blanks with the simple past or past perfect form of the verbs given in brackets.

(i) After Rohan A. __________ (finish) his homework, he B. __________(decide) to go for a walk. He C. __________ (leave) the house and D. __________ (realise) he E. __________ (forget) his keys inside.
(ii) By the time we A. __________ (reach) the station, the train B. __________ (already/leave). We C. __________ (wait) for the next one to arrive.
Ans: (i) After Rohan had finished his homework, he decided to go for a walk. He left the house and realised he had forgotten his keys inside.
(ii) By the time we reached the station, the train had already left. We waited for the next one to arrive.

3: Combine the pairs of sentences using the time expressions in the boxes given below and rewrite them using the past perfect tenses.

Ans: (i) Rohan had packed his suitcase before he left for the airport.
(ii) We had started work before he arrived in the morning.
(iii) They had set up the tents before the others brought food and medicine.
(iv) The students had become quiet when they heard the teacher coming.
(v) The villagers had left the village by the time the flood submerged the entire area.

Let us listen (Page 105)

• Anita accepts Toby as her friend.
• Anita asks Toby about one of his facial features.
• Toby shares that he can see much clearer with a closed eye.

False Statements:

• Toby misses his school. (Incorrect - He says he misses his people and home, not school.)
• Toby tells Anita that she had a banana for breakfast. (Incorrect - He says she had an apple.)

II) Listen to the conversation again and fill in the blanks with the exact words you hear. 
1. Toby: I miss my _________________ and home. 
2. Toby: Well, we _________________ don't need to eat anything. We get our _________________ from the Sun. 
3. Anita: Oh! Don't you ever feel like having ice creams and _________________? 
4. Anita: Okay, tell me one thing. How are you able to see with only_________________ eye? 
5. Toby: I can see beyond mountains and _________________, woods and even _________________. 

Ans: 

1. Toby: I miss my people and home.
2. Toby: Well, we Martians don't need to eat anything. We get our energy from the Sun.
3. Anita: Oh! Don't you ever feel like having ice cream and chocolates?
4. Anita: Okay, tell me one thing. How are you able to see with only one eye?
5. Toby: I can see beyond mountains and clouds, woods and even metals.

Let us speak (Page 105)

QI: I Read the following sentences from the extract.

As usual, I had to be involved, though I'd have preferred to finish my novel. 
"We're old enough to look after ourselves, Ma," I said. 

The word 'though' is pronounced to rhyme with the word 'low'. The word 'enough' is pronounced to rhyme with the word 'puff'.

In English, there are many words ending with -ough, which are pronounced very differently. Listen to the teacher say these words aloud and notice how they are pronounced.

Pronounce these words out loud and put them in the correct boxes given below.

Ans: 

Let us write (Page 106)

Think about different vocations that you see around or you are currently studying. For example: electrician, mechanic, chef, nurse, graphic designer. You may add more vocations to the list given here.

Now, choose a vocation and write a paragraph. You may use the hints given below.

• why you like this vocation 
• what training is needed 
• what tools and equipment are required 
• who would your co-workers be 
• highlight the importance of teamwork 
• how you would deal with the customers 
• how you plan to pursue it with a sense of pride

Ans: 

I want to become a chef because I love cooking and enjoy creating new dishes. Chefs bring joy to people through tasty and healthy food. To become a good chef, I would need to attend a cooking school or take special training in culinary arts. I would learn about different recipes, food safety, and kitchen skills.

Chefs use many tools like knives, frying pans, ovens, blenders, and measuring cups. My co-workers would be other chefs, kitchen assistants, waiters, and restaurant managers. Teamwork is very important in a kitchen. Everyone must work together and help each other so that food is prepared on time and served properly.

As a chef, I would always be polite and respectful to customers. I would listen to their feedback and try to improve. I plan to work hard, stay creative, and feel proud of my job. Cooking for others is not just work-it's a way to make people happy.

Let us explore (Page 107)

Human beings are naturally very curious and creative, and this has led to many scientific and technological inventions. You must have heard about many famous inventions. Some of them are mentioned below. You may look for the names of more such Indian inventors and their inventions.

• Sushruta (sixth century B.C.), was a pioneer figure in medical science. His innovations in surgery paved the way for modern surgery.

• Dr. Janaki Ammal (Padma Shri) was a brilliant woman scientist of India who made a significant contribution to the field of cytogenetics. 

• Under the directorship of Dr. A.P.J. Abdul Kalam (Bharat Ratna), Indian Space Research Organisation (ISRO) launched the satellite Rohini in near-earth orbit with India's first Satellite Launch Vehicle in 1980 (the project was named 'SLV-III')

• Dr. Narinder Singh Kapany (Padma Vibhushan) is known as Father of Fibre Optics. He played a pivotal role in inventing fibre optics. He was named one of the seven 'Unsung Heroes of the Twentieth Century' for his invention.