Back to MECHANICAL PROPERTIES OF SOLIDS

JEE PHYSICS MCQ: MECHANICAL PROPERTIES OF SOLIDS

1 Medium

1 of 1

Analyzing +4 | -1

Assertion: Two wires

A

and

B

have the same cross-sectional area and are made of the same material but the length of wire

A

is twice that of

B

. For a given load, the strain in wire

A

is twice that in

B

.
Reason: For a given load, the extension in a wire is not proportional to its length.

View answer and explanation

Correct option: D

If both assertion and reason are false

Option D is correct because both the assertion and the reason are false. Strain is directly proportional to length when other factors are constant.

More Questions from MECHANICAL PROPERTIES OF SOLIDS

Practice All Chapter MCQs →

A wire is stretched under a force. If the wire suddenly snaps the temperature of the wire The increases in length is

l

of a wire of length

L

by the longitudinal stress. Then the stress is proportional to A steel wire of length

l

and cross sectional area

\mathrm{A}

is stretched by

1 \mathrm{~cm}

under a given load. When the same load is applied to another steel wire of double its length and half of its cross section area, the amount of stretching (extension) is Assertion: From the relation

Y=\frac{F l}{A \Delta l},

we can say that, if length of a wire is doubled, its Young's modulus of elasticity will also becomes two times.

Reason: Modulus of elasticity is a material property. A wire can be broken by applying a load of 200 N. The force required to break another wire of the same length and same material, but double in diameter, is Assertion(A): If radius of cylindrical wire is doubled, then this wire can bear four times stress.

Reason(R): By doubling the radius, area of cross-section will become four times.