The equivalent resistance between the points X  and  Y in the following circuit diagram will be

• 10 Ω

• 5 Ω

• 7 Ω

• 3 Ω

82.

Shear modulus is zero for

• solids

• liquids

• gases

• liquids and gases

For a constant hydraulic stress on an object, the fractional change in the object's volume ( ΔV/V ) and its bulk modulus (B) are related as

• $\frac{∆\mathrm{V}}{\mathrm{V}} \propto \mathrm{B}$

• $\frac{∆\mathrm{V}}{\mathrm{V}} \propto \frac{1}{\mathrm{B}}$

• $\frac{∆\mathrm{V}}{\mathrm{V}} \propto {\mathrm{B}}^2$

• $\frac{∆\mathrm{V}}{\mathrm{V}}\propto {\mathrm{B}}^{-2}$

Assertion: The size of a hydrogen balloon increases as it rises in air. 

Reason:  The material of the balloon can be easily stretched.

• if both assertion and reason are true and the reason is the correct explanation of the assertion

• if both assertion and reason are true and the reason is not the correct explanation of the assertion

• if assertion is true but reason is false

• if both assertion and reason are false statements

The breaking stress of a wire depends upon

• length of  the wire

• material of the wire

• radius of the wire

• shape of the cross-section

Assertion: Stress is the internal force per unit area of a body.

Result: Rubber is more elastic than steel.

• If both the assertion and reason are true and reason is a correct explanation of the assertion.

• If both assertion and reason are true but assertion is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both assertion and reason are false.

A body weighs 200 N at the surface of earth. If it be placed in an artificial satellite revolving at height where acceleration due to gravity is half of that at earth's surface. It will weigh

• 2$\times$10⁹ N/m²

• 2 $\times$10⁸ N/m²

• 2$\times$10⁶ N/m²

• 2$\times$ 10⁴ N/m²

A metal wire of length l, area of cross-section A and Young's modulus Y behaves as a spring of spring constant k given by

• $\mathrm{k}= \frac{\mathrm{YA}}{\mathrm{l}}$

• $\mathrm{k}= \frac{2\mathrm{YA}}{\mathrm{l}}$

• $\mathrm{k}= \frac{\mathrm{YA}}{2\mathrm{l}}$

• $\mathrm{k}= \frac{\mathrm{Yl}}{\mathrm{A}}$

The breaking strength of a rod of diameter 2 cm is 2x 10⁵ N. Then that for rod of same material but diameter 4 cm will be

• 2 × 10⁵ N

• 1 × 10⁵ N

• 8 × 10⁵ N

• 0.5 × 10⁵ N

A metallic rod of Young's modulus 2x10¹¹ N/m² undergoes a strain of 0.5%. Then the energy stored per unit volume in the rod will be

• 2.5 × 10⁶ J/m³

• 5 × 10⁸ J/m³

• 2.5 × 10⁸ J/m³

• 0.5 × 10¹¹ J/m³