Insert a circular loop of copper wire through two holes drilled in a cardboard sheet. Connect the ends X and Y of loop with a battery, key, rheostat and ammeter as shown in adjoining figure. Sprinkle some iron filings on cardboard sheet. when a current is passed through the loop, the iron filings arRead more
Insert a circular loop of copper wire through two holes drilled in a cardboard sheet. Connect the ends X and Y of loop with a battery, key, rheostat and ammeter as shown in adjoining figure. Sprinkle some iron filings on cardboard sheet. when a current is passed through the loop, the iron filings arrange themselves in a definite pattern, which gives the magnetic field pattern. The direction of field at the centre point can be obtained by placing a small compass needle there. The rule which helps to determine the direction of magnetic field is the ‘right hand thumb rule’. As per this rule let us consider our right hand with thumb stretched perpendicular to wrapped fingers. If now wrapped fingers give the direction of current flow in the loop then thumb will point in the direction of magnetic field. A galvanometer, an electric motor, an electric bell, an electric fan etc., are common devices that use current carrying conductors and magnetic fields.
(a) Organ where growth hormone is synthesised in: (i) Man - Pituitary gland. (ii) Plants - Apical meristem like shoot tip and root tip. (b) (i) When a plant is exposed to unidirectional light, the auxin present at the shoot tip detect the stimulus. (ii) The auxin diffuses to shady side of the shoot.Read more
(a) Organ where growth hormone is synthesised in:
(i) Man – Pituitary gland.
(ii) Plants – Apical meristem like shoot tip and root tip.
(b) (i) When a plant is exposed to unidirectional light, the auxin present at the shoot tip detect the stimulus.
(ii) The auxin diffuses to shady side of the shoot.
(iii) This brings about growth of cells on the shady side. Thus this side grows more than the illuminated side.
(iv) This brings about bending of shoot towards the source of light.
The hormone that brings about such growth is Auxin.
The type of movement is Tropic Movement i.e., Phototropic movement.
A fuel is that substance which, on combustion can provide sufficient energy in a convenient form for sustained use over a long period of time. Two important characteristics of a good fuel are: (i) The fuel is available easily at an economic price and can be conveniently transported and stored. (ii)Read more
A fuel is that substance which, on combustion can provide sufficient energy in a convenient form for sustained use over a long period of time.
Two important characteristics of a good fuel are:
(i) The fuel is available easily at an economic price and can be conveniently transported and stored.
(ii) What is the amount and rate of release of heat energy by the fuel on burning and whether any smoke is produced or not.
When dilute hydrochloric acid is added to granulated zinc placed in a test tube’ the observation made is:
(d) Zinc reacts with dil. Hydrochloric acid to evolve a colourless and odourless gas which appears as bubbles
(d) Zinc reacts with dil. Hydrochloric acid to evolve a colourless and odourless gas
See lesswhich appears as bubbles
The flow of current in a circular loop of wire creates a magnetic field at its centre. How can the existence of this field be detected? Slate the rule which helps to determine the direction of this magnetic field. Name four common devices that use current carrying conductors and magnetic fields.
Insert a circular loop of copper wire through two holes drilled in a cardboard sheet. Connect the ends X and Y of loop with a battery, key, rheostat and ammeter as shown in adjoining figure. Sprinkle some iron filings on cardboard sheet. when a current is passed through the loop, the iron filings arRead more
Insert a circular loop of copper wire through two holes drilled in a cardboard sheet. Connect the ends X and Y of loop with a battery, key, rheostat and ammeter as shown in adjoining figure. Sprinkle some iron filings on cardboard sheet. when a current is passed through the loop, the iron filings arrange themselves in a definite pattern, which gives the magnetic field pattern. The direction of field at the centre point can be obtained by placing a small compass needle there. The rule which helps to determine the direction of magnetic field is the ‘right hand thumb rule’. As per this rule let us consider our right hand with thumb stretched perpendicular to wrapped fingers. If now wrapped fingers give the direction of current flow in the loop then thumb will point in the direction of magnetic field. A galvanometer, an electric motor, an electric bell, an electric fan etc., are common devices that use current carrying conductors and magnetic fields.
See less(a) Name one organ each where growth hormone is synthesised in man and plant. (b) List the sequence of events that occur when a plant is exposed to unidirectional light, leading to bending of a growing shoot, Also name the hormone and the type of movement.
(a) Organ where growth hormone is synthesised in: (i) Man - Pituitary gland. (ii) Plants - Apical meristem like shoot tip and root tip. (b) (i) When a plant is exposed to unidirectional light, the auxin present at the shoot tip detect the stimulus. (ii) The auxin diffuses to shady side of the shoot.Read more
(a) Organ where growth hormone is synthesised in:
See less(i) Man – Pituitary gland.
(ii) Plants – Apical meristem like shoot tip and root tip.
(b) (i) When a plant is exposed to unidirectional light, the auxin present at the shoot tip detect the stimulus.
(ii) The auxin diffuses to shady side of the shoot.
(iii) This brings about growth of cells on the shady side. Thus this side grows more than the illuminated side.
(iv) This brings about bending of shoot towards the source of light.
The hormone that brings about such growth is Auxin.
The type of movement is Tropic Movement i.e., Phototropic movement.
(a) Name one salt each of the following types: (i) which gives acidic solution in water. (ii) which gives alkaline solution in water. (iii) which gives neutral solution in water. (b) Name one natural source of each of the following acids: (i) Citric acid (ii) Oxalic acid (iii) Lactic acid (iv) Tartaric acid (v) Acetic acid.
(a) (i) Ammonium chloride (ii) Sodium acetate (iii) Sodium chloride. (b) (i) Citric acid - Orange (ii) Oxalic acid - Tomato (iii) Lactic acid - Sour milk (curd) (iv) Tartaric acid - Tamerind (v) Acetic acid - Vinegar.
(a) (i) Ammonium chloride
See less(ii) Sodium acetate
(iii) Sodium chloride.
(b) (i) Citric acid – Orange
(ii) Oxalic acid – Tomato
(iii) Lactic acid – Sour milk (curd)
(iv) Tartaric acid – Tamerind
(v) Acetic acid – Vinegar.
Define fuel. List any two characteristics that you would look for in a good fuel.
A fuel is that substance which, on combustion can provide sufficient energy in a convenient form for sustained use over a long period of time. Two important characteristics of a good fuel are: (i) The fuel is available easily at an economic price and can be conveniently transported and stored. (ii)Read more
A fuel is that substance which, on combustion can provide sufficient energy in a convenient form for sustained use over a long period of time.
See lessTwo important characteristics of a good fuel are:
(i) The fuel is available easily at an economic price and can be conveniently transported and stored.
(ii) What is the amount and rate of release of heat energy by the fuel on burning and whether any smoke is produced or not.