The electrical resistance in ohms of a certain thermometer varies with temperature according to the approximate law:

$\mathrm{R}={\mathrm{R}}_{0}\left[1+\mathrm{\alpha }\left(\mathrm{T}-{\mathrm{T}}_{0}\right)\right]$

The resistance is 101.6  at the triple-point of water 273.16 K, and 165.5  at the normal melting point of lead (600.5 K). What is the temperature when the resistance is 123.4 ?

Subtopic:  Thermal Expansion |
50%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A steel tape $$1$$ m long is correctly calibrated for a temperature of $$27^\circ \text{C}$$. The length of a steel rod measured by this tape is found to be $$63.0$$ cm on a hot day when the temperature is $$45^\circ \text{C}$$. What is the actual length of the steel rod on that day?
(Coefficient of linear expansion of steel = $$1.20\times 10^{-5}~\text{K}^{-1}$$).

1. $$62.485$$ cm
2. $$60.762$$ cm
3. $$65.935$$ cm
4. $$63.013$$ cm

Subtopic:  Thermal Expansion |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A large steel wheel is to be fitted onto a shaft of the same material. At 27 °C, the outer diameter of the shaft is 8.70 cm and the wheel's central hole has a diameter of 8.69 cm. The shaft is cooled using ‘dry ice’. At what temperature of the shaft does the wheel slip on the shaft?
(Assume the coefficient of linear expansion of the steel to be constant over the required temperature range  and $$\alpha$$ steel = $$1.20 \times 10^{-5} K^{-1}$$)
1. 68°C
2. -70°C
3.  -69°C
4. -67°C

Subtopic:  Thermal Expansion |
51%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A hole is drilled in a copper sheet. The diameter of the hole is 4.24 cm at 27.0 °C. What is the change in the diameter of the hole when the sheet is heated to 227 °C?

(Co-efficient of linear expansion of copper= )

1. 0.0144 cm
2. 0.0234 cm
3. 0.0123 cm
4. 0.0111 cm

Subtopic:  Thermal Expansion |
60%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

The coefficient of volume expansion of glycerine is $$49\times 10^{-5}$$ K–1. What is the fractional change in its density for a $$30^\circ \text{C}$$ rise in temperature?
1. $$1.44\times10^{-3}$$
2. $$1.57\times10^{-3}$$
3. $$1.57\times10^{-2}$$
4.
$$1.44\times10^{-2}$$

Subtopic:  Thermal Expansion |
62%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints