List of top Science Questions

What do you mean by sex chromosomes? Explain the process of sex determination in humans.
Write the chemical name and molecular formula of baking powder. What happens when baking powder is heated?
Write a short note on valency of carbon.
Explain electrochemical series and write its two applications.
Write the name, (ii) working, and (iii) colours of the insulation of the wires used in the domestic electrical distribution.
How can the three resistances 2 Ω, 3 Ω, and 6 Ω be connected, so that (i) total resistance of 4 Ω is obtained, and (ii) total resistance of 1 Ω is obtained?
What do you mean by alloys? Write the names and uses of two main alloys of copper.
Write the IUPAC name of the following compounds:
(a) HCHO
(b) CH3 - CH = CH2
On which factors does the magnetic field due to a current-carrying conductor depend? Write and explain the name of the law used to find the direction of the magnetic field.
Write the structural formulae of the following compounds:
(i) Ethanoic acid
(ii) Methanal
(iii) 1-Chloropropane
(iv) Nitromethane
The image formed of an object at a distance of 25 cm from a convex mirror is half the length of the object. Determine (i) the distance of the image from the mirror, and (ii) the focal length of the mirror.
Example of unisexual flower is:
Buds on leaf develop in:
Which of the following constitutes a food chain?
On placing a concave lens in the path of convergent rays, they focus on the axis in the back, 20 cm from the lens.
In the absence of a lens, where do the rays focus? The focal length of the lens is 30 cm.
Normal blood pressure of a healthy human is:
Antimony is:
The pH value of pure water is:
Energy currency in cellular process is:
Pollen sac contains:
Bile juice is secreted by:
The homologous series in the following is:
Unit of intensity of magnetic field is:
Chemical formula of Lead Nitrate is:
Ampere-second is the unit of: