(b) Because all other parts of the leaf had same resources available other than light, which was, present only in exposed parts. These parts showed presence of starch thereby proving that light is necessary for photosynthesis.
(b) Because all other parts of the leaf had same resources available other than light, which was, present only in exposed parts. These parts showed presence of starch thereby proving that light is necessary for photosynthesis.
(b) As the electric current is flowing horizontally in east to west direction. Applying right hand thumb rule, we find that (i) the direction of magnetic field at a point directly below the wire is from north to south. (ii) the direction of magnetic field at a point directly above the wire is from sRead more
(b) As the electric current is flowing horizontally in east to west direction. Applying right hand thumb rule, we find that
(i) the direction of magnetic field at a point directly below the wire is from north to south.
(ii) the direction of magnetic field at a point directly above the wire is from south to north.
(a) Tropism or tropic movements are directional growth movements in which the direction of movement is determined by the direction of stimulus. Geotropism, phototropism, hydrotropism, chemotropism are different types of tropic movements. (b) Tropism: - (1) It is a growth dependent process that is deRead more
(a) Tropism or tropic movements are directional growth movements in which the
direction of movement is determined by the direction of stimulus. Geotropism, phototropism,
hydrotropism, chemotropism are different types of tropic movements.
(b) Tropism: – (1) It is a growth dependent process that is determined by the direction of stimulus.
(2) It is directional in nature.
(3) Such movements exhibit a slow response towards any stimulus.
Nastic Moaement:-
(1) It is a growth independent process.
(2) It is non-directional in nature.
(3) Such movements exhibit an immediate response towards a stimulus.
Energy obtained by burning fossil fuels:- (i) The energy obtained is of high intensity and is obtained only in a limited surface area for a limited time (ii) Energy obtained by burning fossil fuels is exhaustible. (iii) Fossil fuels are non-renewable. (iv) During burning of fossil fuels lot of smokeRead more
Energy obtained by burning fossil fuels:-
(i) The energy obtained is of high intensity and is obtained only in a limited surface area for a limited time
(ii) Energy obtained by burning fossil fuels is exhaustible.
(iii) Fossil fuels are non-renewable.
(iv) During burning of fossil fuels lot of smoke is produced and various gases are
produced due to which air pollution is caused.
Solar energy:-
(i) Solar energy is diffused in nature. But it is received everywhere on earth at all times.
(ii) Solar energy is non-exhaustible.
(iii) Solar energy is renewable.
(iv) Solar energy causes no pollution of any sort.
(i) Advantage ; A solar water heater does not require any fuel or elasticity. Limitation: A solar water heater cannot operate during night time and on cloudy days. (ii) A solar water heater utilises solar energy which is a renewable and clean source of energy and helps in conservation of environmentRead more
(i) Advantage ; A solar water heater does not require any fuel or elasticity. Limitation: A solar water heater cannot operate during night time and on cloudy days.
(ii) A solar water heater utilises solar energy which is a renewable and clean source of energy and helps in conservation of environment.
(iii) Kapil desires that we should encourage non-conventional, non-polluting and clean source of energy. Thus, he is an environmentalist and a responsible citizen.
(i) Main switch in domestic circuits is used to switch on or switch off the power supply. (ii) Mains fuse acts as a safety device in domestic circuit and prevents damage to the appliances and the electric circuit due to overloading and short circuiting. (iii) The electricity meter installed in the dRead more
(i) Main switch in domestic circuits is used to switch on or switch off the power supply.
(ii) Mains fuse acts as a safety device in domestic circuit and prevents damage to the appliances and the electric circuit due to overloading and short circuiting.
(iii) The electricity meter installed in the domestic circuit is used to measure the quantity of electrical energy being used in the circuit during a given time.
(a) Deficiency of iodine causes goitre. This disorder is commonly prevalent in northern hilly areas. It causes enlargement of thyroid gland which results in swelling of neck region. (b) Thyroid gland secretes iodine containing hormone called thyroxine. Thyroxine controls basal metabolic rate. It regRead more
(a) Deficiency of iodine causes goitre. This disorder is commonly prevalent in northern hilly areas. It causes enlargement of thyroid gland which results in swelling of neck region.
(b) Thyroid gland secretes iodine containing hormone called thyroxine. Thyroxine controls basal metabolic rate. It regulates carbohydrates, protein and fat metabolism in the body. The hormone also controls physical development, mental development, muscular activity, nervous activity and sexual activity.
(a) Two functions of bile juice are: (i) Helps in emulsification of fats. (ii) Provides alkaline medium. (b) Difference between functions of enzymes pepsin and trypsin Pepsin:- (i) Acts in acidic medium in stomach (ii) Acts on proteins and breaks down to polypeptides and dipeptides. Trypsin:- (i) AcRead more
(a) Two functions of bile juice are:
(i) Helps in emulsification of fats.
(ii) Provides alkaline medium.
(b) Difference between functions of enzymes pepsin and trypsin
Pepsin:- (i) Acts in acidic medium in stomach
(ii) Acts on proteins and breaks down to polypeptides and dipeptides.
Trypsin:- (i) Acts in alkaline medium in small intestine.
(ii) Acts on partially digested proteins and breaks down to amino acids
(i) Tamished copper vessel has a layer of copper carbonate around it. On rubbing with lemon (which contains citric acid), a reaction takes place between the carbonate layer and citric acid. Carbonate layer is removed and the vessel shines again. (ii) Alkalies are water soluble bases. As all bases arRead more
(i) Tamished copper vessel has a layer of copper carbonate around it. On rubbing with lemon (which contains citric acid), a reaction takes place between the carbonate layer and citric acid. Carbonate layer is removed and the vessel shines again.
(ii) Alkalies are water soluble bases. As all bases are not soluble in water, therefore, we can say that all bases are not alkalies. However, all alkalies come under the general category of bases.
(iii) Honey-bee sting contains methanoic acid. On applying baking soda over the stung area, methanoic acid is neutralised and relief is felt.
A part of de-starched leaf of a potted plant was covered with black paper strips on both sides and the plant was kept in sunlight for 8 hours. The leaf was then tested with iodine after boiling it in alcohol. Only the uncovered part of the leaf turned blue black. The inference is that:
(b) Because all other parts of the leaf had same resources available other than light, which was, present only in exposed parts. These parts showed presence of starch thereby proving that light is necessary for photosynthesis.
(b) Because all other parts of the leaf had same resources available other than light, which was, present only in exposed parts. These parts showed presence of starch thereby proving that light is necessary for photosynthesis.
See lessThe products of reaction between zinc and sodium hydroxide solution are:
(b) The reaction takes place as under Zn + 2NaOH ⟶ Na₂ZnO₂ + H₂
(b) The reaction takes place as under
See lessZn + 2NaOH ⟶ Na₂ZnO₂ + H₂
(a) Write three distinguishing features between an alternating current and a direct current. (b) A current through a horizontal power line flows in east to west direction. What is the direction of magnetic field at a point directly below it and at a point directly above it? Name the rule you have applied in this case.
(b) As the electric current is flowing horizontally in east to west direction. Applying right hand thumb rule, we find that (i) the direction of magnetic field at a point directly below the wire is from north to south. (ii) the direction of magnetic field at a point directly above the wire is from sRead more
(b) As the electric current is flowing horizontally in east to west direction. Applying right hand thumb rule, we find that
See less(i) the direction of magnetic field at a point directly below the wire is from north to south.
(ii) the direction of magnetic field at a point directly above the wire is from south to north.
(a) What is tropism? (b) Mention the differences between tropism and nastic movement in tabulated form.
(a) Tropism or tropic movements are directional growth movements in which the direction of movement is determined by the direction of stimulus. Geotropism, phototropism, hydrotropism, chemotropism are different types of tropic movements. (b) Tropism: - (1) It is a growth dependent process that is deRead more
(a) Tropism or tropic movements are directional growth movements in which the
See lessdirection of movement is determined by the direction of stimulus. Geotropism, phototropism,
hydrotropism, chemotropism are different types of tropic movements.
(b) Tropism: – (1) It is a growth dependent process that is determined by the direction of stimulus.
(2) It is directional in nature.
(3) Such movements exhibit a slow response towards any stimulus.
Nastic Moaement:-
(1) It is a growth independent process.
(2) It is non-directional in nature.
(3) Such movements exhibit an immediate response towards a stimulus.
Differentiate between energy obtained by burning fossil fuels and that obtained as solar energy.
Energy obtained by burning fossil fuels:- (i) The energy obtained is of high intensity and is obtained only in a limited surface area for a limited time (ii) Energy obtained by burning fossil fuels is exhaustible. (iii) Fossil fuels are non-renewable. (iv) During burning of fossil fuels lot of smokeRead more
Energy obtained by burning fossil fuels:-
See less(i) The energy obtained is of high intensity and is obtained only in a limited surface area for a limited time
(ii) Energy obtained by burning fossil fuels is exhaustible.
(iii) Fossil fuels are non-renewable.
(iv) During burning of fossil fuels lot of smoke is produced and various gases are
produced due to which air pollution is caused.
Solar energy:-
(i) Solar energy is diffused in nature. But it is received everywhere on earth at all times.
(ii) Solar energy is non-exhaustible.
(iii) Solar energy is renewable.
(iv) Solar energy causes no pollution of any sort.
Kapil was feeling proud after the installation of solar water heater on his roof top. He knows that he has contributed towards the conservation of environment. Now answer the following questions:: (i) Write one advantage and one limitation of using a solar water heater. (ii) How has Kapil contributed towards the conservation of environment? (iii) State the values that prompted Kapil’s action.
(i) Advantage ; A solar water heater does not require any fuel or elasticity. Limitation: A solar water heater cannot operate during night time and on cloudy days. (ii) A solar water heater utilises solar energy which is a renewable and clean source of energy and helps in conservation of environmentRead more
(i) Advantage ; A solar water heater does not require any fuel or elasticity. Limitation: A solar water heater cannot operate during night time and on cloudy days.
See less(ii) A solar water heater utilises solar energy which is a renewable and clean source of energy and helps in conservation of environment.
(iii) Kapil desires that we should encourage non-conventional, non-polluting and clean source of energy. Thus, he is an environmentalist and a responsible citizen.
State the significance of the following devices in domestic circuits: (i) Main switch (ii) Mains fuse (iii) Electricity meter.
(i) Main switch in domestic circuits is used to switch on or switch off the power supply. (ii) Mains fuse acts as a safety device in domestic circuit and prevents damage to the appliances and the electric circuit due to overloading and short circuiting. (iii) The electricity meter installed in the dRead more
(i) Main switch in domestic circuits is used to switch on or switch off the power supply.
See less(ii) Mains fuse acts as a safety device in domestic circuit and prevents damage to the appliances and the electric circuit due to overloading and short circuiting.
(iii) The electricity meter installed in the domestic circuit is used to measure the quantity of electrical energy being used in the circuit during a given time.
(a) Name the disease by which a person is likely to suffer due to the deficiency of iodine. Also mention its symptoms. (b) Name the hormone secreted by thyroid gland and state its function.
(a) Deficiency of iodine causes goitre. This disorder is commonly prevalent in northern hilly areas. It causes enlargement of thyroid gland which results in swelling of neck region. (b) Thyroid gland secretes iodine containing hormone called thyroxine. Thyroxine controls basal metabolic rate. It regRead more
(a) Deficiency of iodine causes goitre. This disorder is commonly prevalent in northern hilly areas. It causes enlargement of thyroid gland which results in swelling of neck region.
See less(b) Thyroid gland secretes iodine containing hormone called thyroxine. Thyroxine controls basal metabolic rate. It regulates carbohydrates, protein and fat metabolism in the body. The hormone also controls physical development, mental development, muscular activity, nervous activity and sexual activity.
(a) State two functions of bile juice. (b) Differentiate between the functions of enzymes pepsin and trypsin.
(a) Two functions of bile juice are: (i) Helps in emulsification of fats. (ii) Provides alkaline medium. (b) Difference between functions of enzymes pepsin and trypsin Pepsin:- (i) Acts in acidic medium in stomach (ii) Acts on proteins and breaks down to polypeptides and dipeptides. Trypsin:- (i) AcRead more
(a) Two functions of bile juice are:
See less(i) Helps in emulsification of fats.
(ii) Provides alkaline medium.
(b) Difference between functions of enzymes pepsin and trypsin
Pepsin:- (i) Acts in acidic medium in stomach
(ii) Acts on proteins and breaks down to polypeptides and dipeptides.
Trypsin:- (i) Acts in alkaline medium in small intestine.
(ii) Acts on partially digested proteins and breaks down to amino acids
State reason for the following: (i) A tarnished copper vessel begins to shine again when rubbed with lemon. (ii) All alkalies are bases but all bases are not alkalies. (iii) Use of a mild base like baking soda on the honey-bee stung area gives relief.
(i) Tamished copper vessel has a layer of copper carbonate around it. On rubbing with lemon (which contains citric acid), a reaction takes place between the carbonate layer and citric acid. Carbonate layer is removed and the vessel shines again. (ii) Alkalies are water soluble bases. As all bases arRead more
(i) Tamished copper vessel has a layer of copper carbonate around it. On rubbing with lemon (which contains citric acid), a reaction takes place between the carbonate layer and citric acid. Carbonate layer is removed and the vessel shines again.
See less(ii) Alkalies are water soluble bases. As all bases are not soluble in water, therefore, we can say that all bases are not alkalies. However, all alkalies come under the general category of bases.
(iii) Honey-bee sting contains methanoic acid. On applying baking soda over the stung area, methanoic acid is neutralised and relief is felt.