They are found in north eastern states, along the foothills of the Himalayas, Jharkhand, West Orissa, Chhattisgarh and on the eastern slopes of Western Ghats.
They are found in north eastern states, along the foothills of the Himalayas, Jharkhand, West Orissa, Chhattisgarh and on the eastern slopes of Western Ghats.
The plug is removed from the key when the observations are not being taken in Ohm's law experiment. If plug remain inserted in the key, current will continue to flow through resistance wire and consequently wire may be heated up. As a result its resistance will change and we shall be unable to verifRead more
The plug is removed from the key when the observations are not being taken in Ohm’s
law experiment. If plug remain inserted in the key, current will continue to flow through resistance wire and consequently wire may be heated up. As a result its resistance will change and we shall be unable to verify Ohm’s law.
Water rises in bent tube in the beaker as KOH present in flask absorbs CO₂ released by respiring seeds and creates vaccum, which results in water rising in the tube.
Water rises in bent tube in the beaker as KOH present in flask absorbs CO₂ released
by respiring seeds and creates vaccum, which results in water rising in the tube.
We obtain a precipitate only when barium chloride solution is added to sodium sulphate solution Barium chloride + Sodium sulphate ⟶ Barium sulphate (ppt.) + Sodium chloride
We obtain a precipitate only when barium chloride solution is added to sodium
sulphate solution
Barium chloride + Sodium sulphate ⟶ Barium sulphate (ppt.) + Sodium chloride
Liquid in C is most acidic, followed by that in A and B. Greater the acidic strength, smaller is the pH value. Hence pH value of liquid in B is more than that in A and C.
Liquid in C is most acidic, followed by that in A and B. Greater the acidic strength, smaller is the pH value. Hence pH value of liquid in B is more than that in A and C.
Electrical resistance of a conductor is a measure of the opposition offered by it for flow of electric charge through it. Mathematically, resistance is given as: Resistance R = Potential difference across the conductor V/Current I SI unit of resistance is ohm Ω. Resistance of a conductor is said toRead more
Electrical resistance of a conductor is a measure of the opposition offered by it for flow of electric charge through it. Mathematically, resistance is given as:
Resistance R = Potential difference across the conductor V/Current I
SI unit of resistance is ohm Ω. Resistance of a conductor is said to be 1 Ω, if a potential difference of 1 volt is to be applied across its ends to maintain a flow of 1 ampere of current. The resistance R of a conductor is (a) directly proportional to its length L, (b) inversely proportional to its cross-section area A, and (c) depends on the nature of the material of the conductor. Thus,
R ∝ L/a or R = pl = pL/A,
where p is a constant depending upon the nature of the material of conductor and is known as its resistivity.
(i) The resistance of a wire is doubled if its length is double keeping other factors unchanged. It is because R ∝ L.
(ii) If radius of wire is doubled then its cross-section area (A =πr²) becomes 4 times of its original value. Since R ∝ 1/A hence the new resistance of wire becomes 1/4 th, of its original value.
(a) Three common features of respiratory organs of animals : (i) Animals absorbs oxygen from water or air hence have a structure that increases the surface area which is in contact with the oxygen rich atmosphere. (ii) Since exchange of oxygen-carbon dioxide has to take place across this surface, itRead more
(a) Three common features of respiratory organs of animals :
(i) Animals absorbs oxygen from water or air hence have a structure that increases the surface area which is in contact with the oxygen rich atmosphere.
(ii) Since exchange of oxygen-carbon dioxide has to take place across this surface, it is very fine and delicate.
(iii) ln order to protect this surface, it is placed within the body, so there are passages that take air to this area.
(b) Differences between aerobic and anaerobic respiration:
Aerobic respiration:-
(i) Oxygen is used to breakdown glucose.
(ii) Glucose is broken down completely to release large amount of energy.
Anaerobic respiration:-
(i) Do not involve oxygen to breakdown glucose.
(ii) Breakdown of glucose is incomplete to release small amount of energy.
In which regions are moist deciduous forests found?
They are found in north eastern states, along the foothills of the Himalayas, Jharkhand, West Orissa, Chhattisgarh and on the eastern slopes of Western Ghats.
They are found in north eastern states, along the foothills of the Himalayas, Jharkhand, West Orissa, Chhattisgarh and on the eastern slopes of Western Ghats.
See lessWhat are the major types of vegetation found in India?
(i) Tropical Rain forests (ii) Tropical Deciduous forests (iii) Tropical Thorn Forests and Shrubs (iv) Montane Forests (v) Mangrove Forests.
(i) Tropical Rain forests
See less(ii) Tropical Deciduous forests
(iii) Tropical Thorn Forests and Shrubs
(iv) Montane Forests
(v) Mangrove Forests.
In the Ohm’s law experiment it is advised to take out the key from the plug when the observations are not being taken. Why?
The plug is removed from the key when the observations are not being taken in Ohm's law experiment. If plug remain inserted in the key, current will continue to flow through resistance wire and consequently wire may be heated up. As a result its resistance will change and we shall be unable to verifRead more
The plug is removed from the key when the observations are not being taken in Ohm’s
See lesslaw experiment. If plug remain inserted in the key, current will continue to flow through resistance wire and consequently wire may be heated up. As a result its resistance will change and we shall be unable to verify Ohm’s law.
A student took a small piece of solid quick lime in a china dish and poured over it a small amount of water. List two changes he is likely to observe in the china dish immediately after pouring water.
Ans. (l) A brisk reaction takes place and calcium hydroxide is formed with a hissing sound. (ii) China dish becomes hot.
Ans. (l) A brisk reaction takes place and calcium hydroxide is formed with a hissing sound.
See less(ii) China dish becomes hot.
Shubham sets up the apparatus to show that CO ₂is evolved during respiration. After 3 hours he would observe:
Water rises in bent tube in the beaker as KOH present in flask absorbs CO₂ released by respiring seeds and creates vaccum, which results in water rising in the tube.
Water rises in bent tube in the beaker as KOH present in flask absorbs CO₂ released
See lessby respiring seeds and creates vaccum, which results in water rising in the tube.
In the experiment to show that ‘light is necessary for photosynthesis’, the reason for boiling the leaf in alcohol is to:
Alcohol being organic solvent breaks membranes and dissolves chlorophyll so that blue-black colour of starch-iodine complex is clearly noticeable.
Alcohol being organic solvent breaks membranes and dissolves chlorophyll so that
See lessblue-black colour of starch-iodine complex is clearly noticeable.
We will observe a precipitation to occur when:
We obtain a precipitate only when barium chloride solution is added to sodium sulphate solution Barium chloride + Sodium sulphate ⟶ Barium sulphate (ppt.) + Sodium chloride
We obtain a precipitate only when barium chloride solution is added to sodium
See lesssulphate solution
Barium chloride + Sodium sulphate ⟶ Barium sulphate (ppt.) + Sodium chloride
A student took 5 mL of lemon Juice in each of test tubes A, B and C. She added 5 mL of water in A and 20 mL of water in B. She tested for pH value in all the three tubes. She would find that pH value of liquid :
Liquid in C is most acidic, followed by that in A and B. Greater the acidic strength, smaller is the pH value. Hence pH value of liquid in B is more than that in A and C.
Liquid in C is most acidic, followed by that in A and B. Greater the acidic strength, smaller is the pH value. Hence pH value of liquid in B is more than that in A and C.
See lessWhat is meant by resistance of a conductor? Name and define its SI unit. List the factors on which the resistance of a conductor depends. How is the resistance of a wire affected if: (i) its length is doubled, (ii) its radius is doubled?
Electrical resistance of a conductor is a measure of the opposition offered by it for flow of electric charge through it. Mathematically, resistance is given as: Resistance R = Potential difference across the conductor V/Current I SI unit of resistance is ohm Ω. Resistance of a conductor is said toRead more
Electrical resistance of a conductor is a measure of the opposition offered by it for flow of electric charge through it. Mathematically, resistance is given as:
Resistance R = Potential difference across the conductor V/Current I
SI unit of resistance is ohm Ω. Resistance of a conductor is said to be 1 Ω, if a potential difference of 1 volt is to be applied across its ends to maintain a flow of 1 ampere of current. The resistance R of a conductor is (a) directly proportional to its length L, (b) inversely proportional to its cross-section area A, and (c) depends on the nature of the material of the conductor. Thus,
R ∝ L/a or R = pl = pL/A,
See lesswhere p is a constant depending upon the nature of the material of conductor and is known as its resistivity.
(i) The resistance of a wire is doubled if its length is double keeping other factors unchanged. It is because R ∝ L.
(ii) If radius of wire is doubled then its cross-section area (A =πr²) becomes 4 times of its original value. Since R ∝ 1/A hence the new resistance of wire becomes 1/4 th, of its original value.
(a) State three common features of respiratory organs of animals. (b) Write two points of difference between aerobic respiration and anaerobic respiration.
(a) Three common features of respiratory organs of animals : (i) Animals absorbs oxygen from water or air hence have a structure that increases the surface area which is in contact with the oxygen rich atmosphere. (ii) Since exchange of oxygen-carbon dioxide has to take place across this surface, itRead more
(a) Three common features of respiratory organs of animals :
See less(i) Animals absorbs oxygen from water or air hence have a structure that increases the surface area which is in contact with the oxygen rich atmosphere.
(ii) Since exchange of oxygen-carbon dioxide has to take place across this surface, it is very fine and delicate.
(iii) ln order to protect this surface, it is placed within the body, so there are passages that take air to this area.
(b) Differences between aerobic and anaerobic respiration:
Aerobic respiration:-
(i) Oxygen is used to breakdown glucose.
(ii) Glucose is broken down completely to release large amount of energy.
Anaerobic respiration:-
(i) Do not involve oxygen to breakdown glucose.
(ii) Breakdown of glucose is incomplete to release small amount of energy.