Physics Test 19...

The coefficients of linear expansion of brass and steel rods are α₁ and α₂, lengths of brass and steel rods are l₁ and l₂ respectively. If (l₂ - l₁) is maintained the same at all temperatures, Which one of the following relations holds good?

A copper rod of 88 cm and an aluminium rod of an unknown length have an equal increase in their lengths independent of an increase in temperature. The length of the aluminium rod is : (α_Cu = 1.7 × 10^-5K^-1 and α_Al = 2.2 × 10⁻⁵ K⁻¹)

A pendulum clock runs faster by 5 seconds per day at 20^oC and goes slow by 10 seconds per day at 35^oC. It shows the correct time at a temperature of:

A bimetallic strip is shown in the figure. On cooling, which shape will it attain if α_brass > α _steel :

The diagram shows a bimetallic strip used as a thermostat in a circuit. Copper expands more than Invar for the same temperature rise.

What will be switched on when the bimetallic strip becomes hot?

The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is

The value of coefficient of volume expansion of glycerin is 5 × 10⁴K⁻¹. The fractional change in the density of glycerin for a rise of 40°C in its temperature, is

An inverted bell lying at the bottom of a lake 47.6 m deep has 50 cm³ of air trapped in it. The bell is brought to the surface of the lake. The volume of the trapped air will be: (atmospheric pressure = 70 cm of Hg and density of Hg = 13.6 g/cm3)

A U tube is partially filled with water. Oil which is immiscible in water is poured into one side until the water rises by 25 cm on the other side. If the oil level is 12.5 cm higher than the water level, then the relative density of the oil is:

A barometer kept in a stationary elevator reads 76 cm. If the elevator starts accelerating up, the reading will be: