Mock Test 1 — Properties of Matter

A wire of length $L$ and area $A$ has $Y = 2 \times 10^{11}$ Pa. The force needed to double its length is:

A liquid rises to $h$ in a capillary tube of radius $r$. In a tube of radius $r/2$:

Two soap bubbles of radii $r_1$ and $r_2$ ($r_1 < r_2$) are connected. Then:

A body weighs $W$ in air and $0.75W$ in water. Its density:

Two rods of same length, area, but different conductivities $K_1$ and $K_2$ in series; equivalent $K$:

A wire is stretched. Strain energy per unit volume is:

Water boils at lower temperature on a mountain because:

A bimetallic strip used in thermostats works on:

The terminal velocity of a sphere of mass $m$ falling in viscous fluid:

If the temperature of a black body increases from $T$ to $2T$, energy radiated per second becomes:

$1$ kg of water at $100°$C is converted into steam at $100°$C. The latent heat absorbed is $\_ \times 10^6$ J. (Take $L_v = 2.26 \times 10^6$ J/kg, write coefficient as integer)

A cube of ice melts in $40$ min in a room at $25°$C. Time it would take in a room at $40°$C (in min, rounded):

Two wires of same material, length $L$ each, but radii $r$ and $2r$ in series stretched by same force. Ratio of elongations (smaller : larger), as integer:

Assertion (A): A piece of cork floats higher in salt water than in fresh water. Reason (R): The density of salt water is greater than fresh water.

Assertion (A): Drops of water on a clean glass plate spread out. Reason (R): The angle of contact of water with clean glass is small.