English Medium Class 10 - CBSE Question Bank Solutions for Science

Write the balanced chemical equation for the following and identify the type of reaction.

\[\ce{Zinc carbonate(s) -> Zinc oxide(s) + Carbon dioxide(g)}\]

What does one mean by exothermic reaction? Give example.

Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.

Write one equation for decomposition reactions where energy is supplied in the form of heat.

Which part of the brain maintains posture and equilibrium of the body?

How do we detect the smell of an agarbatti (incense stick)?

What is the role of the brain in reflex action?

How are involuntary actions and reflex actions different from each other?

A person needs a lens of power -5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting (i) distant vision and (ii) near vision?

Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?

Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

State the rule to determine the direction of a magnetic field produced around a straight conductor-carrying current.

State the rule to determine the direction of a current induced in a coil due to its rotation in a magnetic field.

Name one gustatory receptor and one olfactory receptor present in human beings.

Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light and electricity

Name the unit of electrical resistance and give its symbol.

Name the physical quantity whose unit is "ohm".

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Calculate the value of the resistance of the resistor.

 Name the law which is illustrated by the above V−I graph.