Class 10 Science

State the laws of refraction of light. Explain the term absolute refractive index of a medium
Write one main difference between asexual and sexual mode of reproduction
Name the hormones secreted by the following endocrine glands
Write the name and structure of a saturated compound in which the carbon atoms
Why are most carbon compounds poor conductors of electricity
The pH of a salt used to make tasty and crispy pakoras is 14
2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube
Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants
If the image formed by a spherical mirror for all positions of the object placed in front of it is always erect and diminished
Write a and b in the given flow chart of neuron through which information travels as an electrical impulse
A compound ‘X’ on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound
Write the energy conversion that takes place in a hydropower plant
The current flowing through a resistor connected in a circuit and the potential difference
A student traces the path of a ray of light through a glass prism
List four precautions which a student should observe while preparing a temporary mount
After examining a prepared slide under the high power of a compound microscope
List in proper sequence four steps of obtaining germinating dicot seeds
What is observed when a pinch of sodium hydrogen carbonate is added to 2 mL of acetic acid
What would a student report nearly after 30 minutes of placing duly cleaned strips of aluminium
A teacher provided acetic acid, water, lemon juice, aqueous solution of sodium hydrogen carbonate
Calculate the equivalent resistance of the following network
Three resistors R1, R2 and R3 are connected in parallel and the combination is connected to a battery
Consider the given circuit and find the current flowing in the circuit and potential difference
How will you infer with the help of an experiment that the same current flows
How do nerve impulses travel in the body
Why is the use of iodised salt advisable
When do we consider a person to be myopic or hypermetropic
The sex of a newborn child is a matter of chance and none of the parents
What are homologous structures ? Give an example
What is hydrotropism ? Design an experiment to demonstrate this phenomenon
The electrons in the atoms of four elements A, B, C and D are distributed in three shells
How does the metallic character of elements vary on moving from
List any three observations which posed a challenge to Mendeleev’s Periodic Law
Write the essential function performed by ozone at the higher levels of the Earth’s atmosphere
What are solar cells ? Explain the structure of solar panel
A 10 cm tall object is placed perpendicular to the principal axis
A student holding a mirror in his hand, directed the reflecting surface of the mirror
What is carpel ? Write the function of its various parts
Where do the substances in plants reach as a result of translocation
What is translocation, Why is it essential for plants
What is transpiration ? List its two functions
List in tabular form three distinguishing features between autotrophic nutrition and heterotrophic nutrition
What is a homologous series of carbon compounds
What are amphoteric oxides
While diluting an acid, why is it recommended that the acid should be added to water
On heating blue coloured powder of copper (II) nitrate in a boiling tube
Silver articles become black when kept in open for some time
Metals like sodium and potassium are stored under oil
Platinum, gold and silver are used to make jewellery
Why are the heating elements of electric toasters and electric irons