T2 CH2 Electricity — Science STD 7 — Question

Assertion (A) : A current carrying wire should be charged.
Reason (R) : The current in a wire is due to flow of free electrons in a definite direction.

Assertion: Air is a mixture of elements only.
Reason: Only nitrogen, oxygen and neon gases exist in air.

• Both assertion and reason are true and reason is the correct explanation of assertion.
• Both assertion and reason are true, but reason is not the correct explanation of assertion
• Assertion is true but reason is false.
• Assertion is false but reason is true.

Assertion: Mercury is solid in room temperature.
Reason: Mercury is a non-metal.

Assertion (A) : No-new substance is formed when water is heated to get steam.
Reason (R) :Conversion of water into steam is a physical change.

Assertion (A) : Xylem does not have vessels in angiosperms.
Reason (R) : They conduct food.

Assertion (A) : Insulators do not allow flow of current through them.
Reason (R) : Insulators have no free charge carrier.

Assertion (A) : Cutting of paper into very small pieces is an irreversible change.
Reason (R) : Physical changes are always reversible.

Assertion and Reason
A: It takes a very long time for nylon clothes to breakdown into microfibers but cotton clothes need only six months to decompose.
R: Nylon made out of petrochemicals is non-biodegradable and cotton cloth is biodegradable.

Assertion : Corm is a condensed form of Bulb.
Reason : It has dry and fleshy scale leaves.