What causes a bimetallic strip to bend?

Brass and Iron together form the bimetallic strip. The rate of expansion and contraction of brass is more when compared to Iron, that is, brass expands more than Iron when heated and contracts faster than iron when cooled. As a result, the bimetallic strip bends with the change in temperature.

Which way does a bimetallic strip bend?

Brass has a thermal expansion coefficient approximately twice as great as steel. Thus, brass will experience a greater expansion in its length than steel will for equal temperature changes. A bimetallic strip of steel and brass will thus bend toward the steel upon heating and toward the brass upon cooling.

Why does a bimetallic strip bend with changes in temperature?

On what principle does a bimetal strip operate?

Bimetal thermometers work on the principle that different metals expand at different rates as they are heated. By using two strips of different metals in a thermometer, the movement of the strips correlates to temperature and can be indicated along a scale.

What is the principle of bimetallic strip?

Definition: A bimetallic strip works on the principle of thermal expansion, which is defined as the change in volume of metal with the change in temperature. The bimetallic strip works on two basic fundamentals of metals.

Why does a bimetallic strip of brass and iron bend on heating?

When the bimetallic strip is heated, brass expands more than steel due to higher thermal coefficient than steel. And hence due to this phenomenon brass side shows higher expansion especially linear expansion than iron and hence forcing the whole bimetallic strip to bend.

What is the role of loose electrons?

What is the role of “loose” electrons in heat conductors? “Loose” electrons move quickly and transfer energy to other electrons that migrate through the material. Metal is very conductive, meaning it transfers heat very well. Air is a poor conductor.

Why a solid metal expands when it is heated?

Metal expands when heated. Length, surface area and volume will increase with temperature. Thermal expansion occurs because heat increases the vibrations of the atoms in the metal. Accounting for thermal expansion is essential when designing metallic structures.

How does the bimetallic strip work in an iron?

A bimetallic strip controls the thermostat. This consists of a strip of brass in contact with a strip of iron. When the temperature is lower than normal room temperature, the length of the brass will be less than the length of the iron, and so the bimetallic strip will become “U-shaped” with the brass on the topside.

Why does a bimetallic strip bend when heated?

The bimetallic strip is made of two metal strips, stuck together. One of the metals expands much more than the other when they are heated. This causes the strip to bend. A bi-metallic strip can be used as a sensor in a thermostat. View more on it here. Thereof, what is a bimetallic strip and why does it bend when heated?

What is a bi-metallic strip?

The bimetallic strip is made of two metal strips, stuck together. One of the metals expands much more than the other when they are heated. This causes the strip to bend. A bi-metallic strip can be used as a sensor in a thermostat.

Why are bimetallic strips used in thermostats?

Bimetallic strips are used as switches in thermostats. bi-metalic strips bend when heated Two metals making up the strip have different rates of expansion, so as heat is applied and the metals expand, one metal will expand faster than the other, causing that side to grow longer faster than the other side. Likewise, how are bimetallic strips useful?

What happens to a flat strip when heated and cooled?

The different expansions force the flat strip to bend one way if heated, and in the opposite direction if cooled below its initial temperature. The metal with the higher coefficient of thermal expansion is on the outer side of the curve when the strip is heated and on the inner side when cooled.