Linear Expansion

Q.

A bimetallic strip bends on heating due to?

1. The uneven expansion of its constituent metals.

2. The even expansion of its constituent metals.

3. The lack of expansion of its constituent metals.

4. None of the above

Q.

A uniform steel wire of cross-sectional area $0.20m{m}^2$ is held fixed by clamping its two ends. Find the extra force exerted by each clamp on the wire if the wire is cooled from ${100}^{\circ }C$ to $0^{\circ }C$. Young's modulus of steel = $2.0\times {10}^{11}N/m^2$. Coefficient of linear expansion of steel = $1.2\times {10}^{-5}{/}^{\circ }C$.

1. 4.8 N

2. 48 N

3. 500 N

4. 480 N

Q. Copper matte contains 1. Only Cu2S 2. Only CuO 3. Cu2S & FeS 4. Cu2S & Cu

Q.

When the length of a solid rod increases on heating, it is known as _________ expansion.

Q. Two rods, one of aluminium and the other made of steel, having initial lengths ${\text{l}}_1$ and ${\text{l}}_2$ are connected together to form a single rod of length $3\text{cm}$. If the length of each rod increases by the same amount when the temperature is raised by a certain value, and if $22\times {10}^{-6}{}^{\circ }{\text{C}}^{-1}$ and $11\times {10}^{-6}{}^{\circ }{\text{C}}^{-1}$ are the coefficients of linear expansion of aluminium and steel, then:

1. ${\text{l}}_1=2\text{cm},{\text{l}}_2=1\text{cm}$
2. ${\text{l}}_1=0.5\text{cm},{\text{l}}_2=2.5\text{cm}$
3. ${\text{l}}_1=1\text{cm},{\text{l}}_2=2\text{cm}$
4. ${\text{l}}_1=2.5\text{cm},{\text{l}}_2=0.5\text{cm}$

Q.

Why is one end of the beams of steel bridge kept on a roller instead of fixing in a pillar.

Q. Two rods, one of aluminium and the other made of steel, having initial length $l_1$ and $l_2$ are connected together to form a single rod of length $l_1+l_2.$ The coefficients of linear expansion for aluminium and steel are ${\alpha }_a$ and ${\alpha }_a$ and respectively. If the length of each rod increases by the same amount when their temperature are raised by $t^{o}C$, then find the ratio of length of aluminium rod to the whold rod.

(IIT JEE 2003)

1. ${\alpha }_s/{\alpha }_a$
2. ${\alpha }_a/{\alpha }_s$
3. ${\alpha }_s/({\alpha }_a+{\alpha }_s)$
4. ${\alpha }_a/({\alpha }_a+{\alpha }_s)$

Q. Two rods, one of aluminium and the other made of steel, having initial length $l_1$ and $l_2$ are connected together to form a single rod of length $l_1+l_2.$ The coefficients of linear expansion for aluminium and steel are ${\alpha }_a$ and ${\alpha }_a$ and respectively. If the length of each rod increases by the same amount when their temperature are raised by $t^{o}C$, then find the ratio of length of aluminium rod to the whold rod.

(IIT JEE 2003)

1. ${\alpha }_s/{\alpha }_a$
2. ${\alpha }_a/{\alpha }_s$
3. ${\alpha }_s/({\alpha }_a+{\alpha }_s)$
4. ${\alpha }_a/({\alpha }_a+{\alpha }_s)$

Q.

Name the two substances which expands on heating.