# Hot water cools from 60$°\mathrm{C}$ to 50$°\mathrm{C}$ in first 10 minutes and from 50$°\mathrm{C}$ to 42$°\mathrm{C}$ in next 10 minutes. The temperature of surrounding is : 1.   2.   3.   4.  $20°\mathrm{C}$

Subtopic:  Newton's Law of Cooling |
77%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A pendulum clock runs faster by 5 seconds per day at $$20^{\circ}\mathrm {C}$$ and goes slow by 10 second per day at $$35^{\circ}\mathrm {C}$$. It shows the correct time at a temperature of:
1. $$27.5^{\circ}\mathrm {C}$$
2. $$25^{\circ}\mathrm {C}$$
3. $$30^{\circ}\mathrm {C}$$
4. $$33^{\circ}\mathrm {C}$$

Subtopic:  Thermal Expansion |
65%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A constrained steel rod of length l, area of cross-section A, Young's modulus Y and coefficient of linear expansion $\alpha$ is heated through $$t^{\circ}\mathrm{C}$$. The work that can be performed by the rod when heated is:
1. (YA$\alpha$t)(l$\alpha$t)
2. $\frac{1}{2}$(YA$\alpha$t)(l$\alpha$t)
3. $\frac{1}{2}$(YA$\alpha$t)$\frac{1}{2}$(l$\alpha$t)
4. 2(YA$\alpha$t)(l$\alpha$t)

Subtopic:  Thermal Stress |
63%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The temperature of a body on Kelvin scale is found to be X K. When it is measured by a Fahrenheit thermometer, it is found to be X0F. Then X is

(1) 301.25

(2) 574.25

(3) 313

(4) 40

Subtopic:  Temperature and Heat |
66%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

When a block of iron floats in Hg at $0°C$, a fraction ${K}_{1}$ of its volumen= is submerged, while at temperature of $60°C$ a fraction ${K}_{2}$ is seen to be submersed. If the coefficient of volume expansion of iron is ${\gamma }_{Fe}$ and that of mercury is ${\gamma }_{Hg}$, then the ratio $\frac{{K}_{1}}{{K}_{2}}$ can be expressed as:

1. $\frac{1+60{\gamma }_{Fe}}{1+60{\gamma }_{Hg}}$

2. $\frac{1-60{\gamma }_{Fe}}{1+60{\gamma }_{Hg}}$

3. $\frac{1+60{\gamma }_{Fe}}{1-60{\gamma }_{Hg}}$

4. $\frac{1+60{\gamma }_{He}}{1-60{\gamma }_{Fe}}$

Subtopic:  Thermal Expansion |
51%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Heat capacity is equal to the product of:

1.  mass and gas constant

2.  mass and specific heat

3.  latent heat and volume of water

Subtopic:  Calorimetry |
90%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

If ${\lambda }_{m}$ is the wavelength, corresponding to which the radiant intensity of a block is at its maximum and its absolute temperature is T, then which of the following graph correctly represents the variation of T?

 1 2 3 4

Subtopic:  Wien's Displacement Law |
74%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A body cools down from $$80^{\circ}\mathrm{C}$$ $\mathrm{to}$ $$70^{\circ}\mathrm{C}$$ in 5 minutes. The temperature of the same body will fall from $$70^{\circ}\mathrm{C}$$$\mathrm{}$ $\mathrm{to}$ $$60^{\circ}\mathrm{C}$$$\mathrm{}$ in:

 1 less than 5 minutes. 2 equal to 5 minutes. 3 more than 5 minutes. 4 can't say anything as the temperature of the surroundings is not known.

Subtopic:  Newton's Law of Cooling |
63%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A black body at temperature 300K radiates heat at the rate E. If its temperature is increased by 600K, the rate of radiation will increase to -

1.  16E

2.  64E

3.  81E

4.  256E

From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A temperature of $$100^{\circ}\text {F}$$ (Fahrenheit scale) is equal to $$T~\text{K}$$ (Kelvin scale). The value of $$T$$ is:
1. $$310.9$$
2. $$37.8$$
3. $$100$$
4. $$122.4$$

Subtopic:  Temperature and Heat |
74%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints