"Thermal Expansion" question number distribution across years

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JAMB questions for "Physics :: Thermal Expansion"

Q1

The ratio of the coefficient of linear expansions of two metals α_{1}/α_{2} is 3.4 . If, when heated through the same temperature change , the ratio of the increase in lengths of the two metals , e_{1}/e_{2} is 1.2, the ratio of the original length l_{1}/l_{2} is

A

3/2

B

3/8

C

8/3

D

2/3

E

**Answer:** D

Q2

A blacksmith heated a metal whose cubic expansivity is 6.3 x 10^{-6} K^{-1}. The area expansivity is

A

4.2 x 10^{-6}K^{-1}

B

2.0 x 10^{-6}K^{-1}

C

6.3 x 10^{-6}K^{-1}

D

2.1 x 10^{-6}K^{-1}

E

**Answer:** A

Q3

Which of the following gas laws is equivalent to the work done?

A

Charles law

B

Pressure law

C

Van der Waal's law

D

Boyle's law

E

**Answer:** C

Q4

Metal rods of length 20m each are laid end to end to form a brigde at 25°C. What gap will be provided between consecutive rails for the bridge to withstand 75°C?

A

0.20m

B

0.22m

C

0.25m

D

0.02m

E

**Answer:** D

Q5

Thermal equilibrium between two objects exists when

A

the heat capacities of both objects are the same

B

one object losses heat continously to the other

C

the temperatures of both objects are equal

D

the quality of heat in both objects is the same

E

**Answer:** D

Q6

On a fairly cool rainy day when the temperature is 20°C, the length of a steel rail road track is 20m. What will be its length on a hot dry day when the temperature is 40°C ?

A

20. 009m

B

20.002m

C

20.013m

D

20.004m

E

**Answer:** D

Q7

If 1.2 x 10^{6} J of heat energy is giver off in 1 sec. from a vessel maintained at a temperature gradient of 30Km^{-1} , the surface area of the vessel is

A

1.0 x 10^{3}m^{2}

B

1.0 X 10^{2}m^{2}

C

9.0 x 10^{4}m^{2}

D

9.0 x 10^{2}m^{2}

E

**Answer:** B

Q8

The linear expansitivity of brass is 2 x 10^{-5} C^{-1}. If the volume of a piece of brass is 15.00cm^{3} at 0°C, what is the volume at 100°C?

A

16.03 cm^{3}

B

16.00 cm^{3}

C

15.09 cm^{3}

D

15.03 cm^{3}

E

**Answer:** C

Q9

A metal rod 800 mm long is heated from 10°C to 95°C. If it expands y 1.36 mm, the linear expansivity of the metal is

A

2.0 X 10^{2} K^{-1}

B

2.0 X 10^{-2} K^{-1}

C

5.0 X 10^{-3} K^{-1}

D

2.0 X 10^{-5}K^{-1}

E

**Answer:** D

Q10

The melting point of a solid is given as 80°C. If 105 J of heat energy is required at this temperature to melt 10 g of the solid, the specific latent heat of fusion of the solid is

A

1.00 x 10^{3}J kg^{-1}

B

1.25 x 10^{5}J kg^{-1}

C

1.00 x 10^{7}J kg^{-1}

D

8.00 x 10^{8}J kg^{-1}

E

**Answer:** C

Q11

A bridge made of steel is 600 m long . What is the daily variation in its length if the night-time and day-time temperatures are 10°C and 35° respectively. The linear expansivity of steel is 0.000012°C^{-1}

A

0.18 cm

B

1.80 cm

C

18.00 cm

D

1800 cm

E

**Answer:** C

Q12

A brass rod is 2m long at a certain temperature. What is the length for a temperature rise of 100 k, if the expansivity of brass is 18 X 10^{-6 -1} ?

A

2.0036 m

B

2.0018 m

C

2.1800 m

D

2.0360m

E

**Answer:** A

Q13

A bar of initial length l_{0 }is heated through a temperature change Δ t to a new length l. The linear expansivity, α, of the bar is

A

l - l_{0} / l Δ t

B

l - l_{0} / l0 Δ t

C

l_{0} (1 + Δt)

D

l - l_{0} / l (l + Δt)

E

**Answer:** B

Q14

A metallic strip iron and brass was heated. Which of the following diagrams accurately illustrates the shape of the strip after heating?

A

B

C

D

E

**Answer:** B

Q15

The length of a side of a metalic cube at 20°C is 5.0cm. Given that the linear expansivity of the metal is 4.0 X 10^{-5} , find the volume of the cube at 120°C

A

126. 50cm^{3}

B

126.25cm^{3}

C

126.00cm^{3}

D

125.00cm^{3}

E

**Answer:** A

Q16

The expansion of solids can be considered a disadvantage in the

A

balance wheel of a watch

B

fitting of wheels on rims

C

fire alarm

D

thermostat

E

**Answer:** B

Q17

A thin aluminium plate has a surface area of 1.500m^{2} at 20°C. What will be its surface area when it is cooled to -20°C? ( take the linear expansivity of aluminium to be 2.5 X 10^{-5} K^{-1})

A

1.503 m^{2}

B

1.500 m^{2}

C

1.498m^{2}

D

1.497 m^{2}

E

1.490 m^{2}

**Answer:** E

Q18

The linear expansivity of brass is 2 X 10-5 °C^{-1}. If the volume of a piece of brass is 10cm^{3} at 0° C, what will be its volume at 100°C?

A

10.02 cm^{3}

B

10.04 cm^{3}

C

10.06 cm^{3}

D

10.20 cm^{3}

E

102.00 cm^{3}

**Answer:** A

Q19

Which of the following statements clearly describe the behaviour of the fire alarm shown in Fig 8 below given that the linear expansivities of copper and steel are 2.0 x 10^{-5}/°C and 1.2 x 10^{-5}/°C respectively?

I. The bimetallic strip will not be able to close the circuit when there is fire.

II. The bimetallic strip will close the circuit when there is fire

III. If the copper and steel are interchanged, the circuit will close when there is fire.

A

I only

B

II only

C

III only

D

I and III

E

II and III

**Answer:** D

Q20

A rod of length 10cm is heated through 100°C and its final length is 10.26 cm. What is the coefficient of linear expansion of the rod?

A

0.026 per degree centgrade

B

0.00026 per degree centigrade

C

0.26 per degree centigrade

D

1.0026 per degree centgrade

E

0.0026 per degree centigrade

**Answer:** B

Q21

The ratio of the linear expansivity of copper to that of iron is approximately 1.5. A specimen of iron and a specimen of copper expand by the same amount per unit rise in temprature . The ratio of their lengths is

A

3

B

1.5

C

1.32

D

1

E

0.67

**Answer:** E

Q22

A steel plug has a diameter of 5cm at 30oC. At what temperature wil it fit exactly into a hole constant diameter 4.997 cm? {coefficient of linear expansion of steel is 11 x 10 ^{-6} °C -1 }

A

27.3°C

B

-27.3°C

C

-2.7°C

D

7. 32°C

E

2.7°C

**Answer:** B