List of top Science Questions

What is covalent bond? Give two examples of it.
Why is it necessary to balance a chemical equation?
How is the concentration of OH\(^-\) ion affected on adding a base in excess to sodium hydroxide solution?
Mention two reactions that displace chlorine from bleaching powder by giving equations.
Explain scattering of light.
How does the eye control the amount of light entering into it?
Which quantity remains constant in Ohm's law, when temperature is constant? Explain.
What is the source of energy of the sun? Explain.
Write any two properties of magnetic field lines.
What is a non-renewable source of energy? Give two examples of it.
Prove for a concave mirror \[ \frac{1}{v} + \frac{1}{u} = \frac{1}{f} \]
Why is a rainbow colourful?
The device which directly converts solar energy into electricity is:
A bulb filament has a resistance of 1200 ohms. It is connected to a 220 V power supply. How much current will it draw?
The electromotive force of a cell is 1.5 V. The work done on passing a charge of 1 C will be:
Define ampere.
Find the power of a concave lens of 2 m focal length.
Write any three uses of a concave mirror.
An aqueous solution of ammonium chloride is:
Which one of the following is a covalent compound?
A white ray is incident obliquely on a glass slab. Which of the following will occur with the first refraction?
Which of the following is a good conductor of electricity?
In domestic electric circuit, the colour of neutral wire is:
In which device does the split ring act as a commutator?
The radius of curvature of a concave mirror of focal length 20 cm is: