Question 1 :
State True or False. The combination of two or more cells is called a battery.
Question 2 :
State True or False. When current is switched 'on' in a room heater, it produces heat.
Question 3 :
State True or False. The safety device based on the heating effect of electric current is called a fuse.
Question 4 :
Fill in the blanks. Longer line in the symbol for a cell represents its ___________terminal.
Question 5 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cc0df59b460d7261ecf9.png' />
Will the compass needle show deflection when the switch in the circuit shown by figure given above is closed?
Question 7 :
State True or False. To make a battery of two cells, the negative terminal of one cell is connected to the negative terminal of the other cell.
Question 8 :
State True or False. When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks.
Question 9 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cc10f59b460d7261ecfc.png' />
From the above circuit, would any of the bulb glow when the switch is in the 'OFF' position?
Question 10 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cc0ef59b460d7261ecfa.png' />
From the above circuit, what will be the order in which the bulbs A, B and C will glow when the switch is moved to the 'ON position?
Question 11 :
State True or False. An electromagnet does not attract a piece of iron.
Question 13 :
Special type of substances used to test whether a substance is acidic or basic are called-
Question 16 :
The substances which are neither acidic nor basic are called -
Question 17 :
Curd, lemon juice, orange juice and vinegar taste sour because they contain ___________.
Question 18 :
Boojho added dilute sulphuric acid to lime water. Will the reaction mixture become hot or cool?
Question 20 :
Why is an antacid tablet taken when you suffer from acidity?
Question 21 :
Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?
Question 22 :
Sodium hydroxide and hydrochloric acid neutralise each other and form salt and water. State true or false.
Question 23 :
State true or false. Change of colour in an acid and a base depends on the type of the indicator.
Question 24 :
Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?
Question 25 :
When an acidic solution is mixed with a basic solution, both the solutions neutralise the effect of each other. What is this process called?
Question 26 :
State true or false. Indicator is a substance which shows different colours in acidic and basic solutions
Question 29 :
Dorji has a few bottles of soft drink in his restaurant. But, unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants acidic drink, another wants basic and third one wants neutral drink. How will Dorji decide which drink is to be served to whom?
Question 30 :
State true or false. If an indicator changes colour with a base, it does not change colour with an acid.
Question 31 :
State true or false. If an indicator gives a colour change with an acid, it does not give a change with a base.
Question 34 :
In neutralisation reaction, a new substance is formed called as -
Question 37 :
Why calamine solution is applied on the skin when an ant bite?
Question 38 :
Why factory waste is neutralised before disposing it into the water bodies?
Question 40 :
State true or false. Sodium hydroxide and hydrochloric acid neutralise each other and form salt and water.
Question 42 :
Substances which are bitter in taste and feel soapy on touching are known as -
Question 44 :
Indicator is a substance which shows different colours in acidic and basic solutions. State true or false.
Question 47 :
Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution?
Question 50 :
The nature of bitter and soapy substances is said to be -
Question 52 :
State true or false. Both acids and bases change colour of all indicators.
Question 53 :
Consider the following statements:
(a) Both acids and bases change colour of all indicators.
(b) If an indicator gives a colour change with an acid, it does not give a change with a base.
(c) If an indicator changes colour with a base, it does not change colour with an acid.
(d) Change of colour in an acid and a base depends on the type of the indicator.
Which of these statements are correct?
Question 54 :
State true or false. Tooth decay is caused by the presence of a base.
Question 55 :
Tooth decay is caused by the presence of a base. State true or false.
Question 58 :
A large, muscular sheet called ______ forms the floor of the chest cavity.
Question 60 :
$In the absence of oxygen, Glucose --> _______+ carbon dioxide + energy
Question 63 :
During heavy exercise, we get cramps in the legs due to the accumulation of
Question 65 :
How many times, on an average, does an adult human being at rest breathes in and out per minute?
Question 68 :
When we inhale air, it passes through our nostrils into the _________. From the nasal cavity, the air reaches our _____ through the windpipe.
Question 69 :
State whether true or false. During heavy exercise the breathing rate of a person slows down.
Question 71 :
During heavy exercise, we get cramps in the legs due to the accumulation of
Question 72 :
Plants carry out photosynthesis only during the day and respiration only at night.
Question 73 :
Why does an athlete breathe faster and deeper than usual after finishing the race?
Question 76 :
Take three test-tubes. Fill $\frac {3}{4}th$ of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of $CO_2$ ?
Question 80 :
________ in fish help them to use oxygen \dissolved in water.
Question 81 :
In the presence of oxygen, Glucose $-->$ _______+ water + energy
Question 86 :
As a result of the improvement of blood circulation the supply of oxygen to the muscle cells _____.
Question 95 :
Insects have a network of air tubes called ______ for gas exchange.
Question 96 :
Normal range of breathing rate per minute in an average adult person at
Question 101 :
Why do we often sneeze when we inhale a lot of dust-laden air?
Question 103 :
In human body muscle, in the absence of oxygen,Glucose --> _________+ energy
Question 106 :
Take three test tubes. Fill $\frac{3}{4}$th of each with water. Label them A, B and C. Keep a snail in test tube A, a water plant in test tube B and in C, keep snail and plant both. Which test tube would have the highest concentration of $CO_2$?
Question 111 :
Which one is not a part of the process of wool manufacturing?
Question 112 :
Long, fine continuous thread or filaments are obtained from plants and animals is called______
Question 114 :
The process of taking out threads from the cocoon for use as silk is called
Question 115 :
_____ is obtained from the fleece (hair) of sheep or yak.
Question 116 :
The silkworm is (a) a caterpillar, (b) a larva. Choose the correct option.
Question 118 :
The second stage of life history of silk moth is -
Question 122 :
Paheli wanted to buy a gift made of animal fibre obtained without killing the animal, which of the following would be the right gift for her to buy ?
Question 123 :
Hair traps a lot of air, which is ______ conductor of heat.
Question 126 :
Which country's sheep are known best to yield the best wool?
Question 128 :
The Fleece of the sheep along with a thin layer of skin is removed by machines. This proces is called_____
Question 130 :
The under hair of Kashmiri goats are fine and soft. Soft shawls woven from this are fine and called as________
Question 132 :
By _________ we mean the rearing of silkworms for obtaining silk.
Question 133 :
Given below is a sequence of step in the processing of wool. Which are the missing steps? Add them.
Shearing_________, sorting________and________ into yarn.
Question 135 :
The straightening of dyed fibres by passing through metal teeth is known as _______
Question 136 :
The risks faced by workers in any industry are called occupational hazards. True or false ?
Question 137 :
The fleece of the sheep along with a thin layer of skin is removed from its body. This process is called
Question 138 :
Paheli wants to know if the cotton thread and silk thread are spun and woven in Ihe same manner.
Question 141 :
Wool fibre cannot be obtained from which of the following ?
Question 142 :
In the processing of wool from sheep, after scouring, the hairy skin is sent to a factory where hair of different textures are separated or sorted. This is called
Question 148 :
From what type of health problems do the workers suffer while working in a wool industry ?
Question 151 :
Some words related with silk are jumbled up. Choose the correct option: 1. TURECULRISE
Question 152 :
The low grade silk is obtained from the filaments of ________ cocoons.
Question 155 :
Which of the following is the correct type of sheep fibres?
Question 156 :
For obtaining wool, the fleece ot the sheep together with a thin layer of skin is taken of its body. This process is known as ________
