Grade 11 : Physics - Thermal Properties (Set 5)

Question 1

Convert a room temperature reading of $27^\circ ext{C}$ into the absolute Kelvin scale.

Accepted Answer

A) 300.15 K

Answer

B) 273.15 K

Answer

C) 327.15 K

Answer

D) 373.15 K

Question 2

A copper rod of original length $L_0 = 2.0 m$ is heated uniformly.

If the temperature increases from $20^\circ ext{C}$ to $70^\circ ext{C}$ and the coefficient of linear expansion $\alpha = 1.2 imes 10^{-5} ext{ K}^{-1}$, calculate the increase in length $\Delta L$.

Accepted Answer

B) 1.2 mm

Answer

A) 0.6 mm

Answer

C) 2.4 mm

Answer

D) 3.6 mm

Question 3

If the coefficient of linear thermal expansion for an isotropic solid is $\alpha = 2.0 imes 10^{-5} ext{ K}^{-1}$, what is its coefficient of volume expansion $\gamma$?

Accepted Answer

C) $6.0 	imes 10^{-5}	ext{ K}^{-1}$

Answer

A) $2.0 	imes 10^{-5}	ext{ K}^{-1}$

Answer

B) $4.0 	imes 10^{-5}	ext{ K}^{-1}$

Answer

D) $8.0 	imes 10^{-5}	ext{ K}^{-1}$

Question 4

At what temperature does water exhibit its maximum density under standard atmospheric pressure?

Accepted Answer

B) $4^\circ	ext{C}$

Answer

A) $0^\circ	ext{C}$

Answer

C) $100^\circ	ext{C}$

Answer

D) $-4^\circ	ext{C}$

Question 5

Calculate the amount of heat required to raise the temperature of 0.5 kg of liquid water from $20^\circ ext{C}$ to $60^\circ ext{C}$. (Specific heat capacity of water $c = 4200 ext{ J kg}^{-1} ext{K}^{-1}$)

Accepted Answer

B) 84 kJ

Answer

A) 42 kJ

Answer

C) 168 kJ

Answer

D) 210 kJ

Question 6

Which of the following represents the correct SI unit for thermal conductivity ($K$)?

Accepted Answer

B) $	ext{W m}^{-1}	ext{K}^{-1}$

Answer

A) $	ext{J m}^{-1}	ext{K}^{-1}$

Answer

C) $	ext{W m K}^{-1}$

Answer

D) $	ext{J K}^{-1}$

Question 7

How much energy is required to completely melt 2.0 kg of ice at $0^\circ ext{C}$ to water at $0^\circ ext{C}$? (Latent heat of fusion $L_f = 3.33 imes 10^5 ext{ J/kg}$)

Accepted Answer

C) 666 kJ

Answer

A) 333 kJ

Answer

B) 500 kJ

Answer

D) 999 kJ

Question 8

According to Wien's Displacement Law, how is the wavelength $\lambda_m$ corresponding to maximum spectral radiance related to absolute temperature $T$?

Accepted Answer

C) $\lambda_m \propto \frac{1}{T}$

Answer

A) $\lambda_m \propto T$

Answer

B) $\lambda_m \propto T^2$

Answer

D) $\lambda_m \propto \frac{1}{T^2}$

Question 9

A black body at absolute temperature $T$ emits radiant energy at a rate $E$. If the absolute temperature is doubled to $2T$, what is the new rate of energy radiation?

Accepted Answer

D) $16E$

Answer

A) $2E$

Answer

B) $4E$

Answer

C) $8E$

Question 10

A bimetallic strip is constructed by riveting together a strip of brass ($\alpha = 19 imes 10^{-6} ext{ K}^{-1}$) and a strip of iron ($\alpha = 12 imes 10^{-6} ext{ K}^{-1}$).

What happens to the bimetallic strip when it is uniformly heated?

Accepted Answer

A) It bends with the brass strip on the outer (convex) side.

Answer

B) It bends with the iron strip on the outer (convex) side.

Answer

C) It remains perfectly straight but expands in length.

Answer

D) It twists into a tight helical coil.

Question 11

The heat transfer rate $H$ through a uniform solid rod of length $L$, cross-sectional area $A$, and thermal conductivity $K$ with temperature difference $\Delta T$ is given by:

Accepted Answer

A) $H = \frac{K A \Delta T}{L}$

Answer

B) $H = \frac{K L \Delta T}{A}$

Answer

C) $H = \frac{A L \Delta T}{K}$

Answer

D) $H = K A L \Delta T$

Question 12

Two metal rods of identical dimensions are joined end-to-end (in series). Their thermal conductivities are $K_1 = 100 ext{ W m}^{-1} ext{K}^{-1}$ and $K_2 = 300 ext{ W m}^{-1} ext{K}^{-1}$. What is the equivalent thermal conductivity $K_{eq}$?

Accepted Answer

A) $150	ext{ W m}^{-1}	ext{K}^{-1}$

Answer

B) $200	ext{ W m}^{-1}	ext{K}^{-1}$

Answer

C) $250	ext{ W m}^{-1}	ext{K}^{-1}$

Answer

D) $400	ext{ W m}^{-1}	ext{K}^{-1}$

Question 13

Which mechanism of heat transfer can occur through a complete vacuum without requiring any physical medium?

Accepted Answer

C) Radiation

Answer

A) Conduction

Answer

B) Convection

Answer

D) Advection

Question 14

A body cools from $60^\circ ext{C}$ to $50^\circ ext{C}$ in 5 minutes in a room at $20^\circ ext{C}$. Using Newton's Law of Cooling, find the cooling constant $k$ (in $ ext{min}^{-1}$).

Accepted Answer

B) $0.057	ext{ min}^{-1}$

Answer

A) $0.025	ext{ min}^{-1}$

Answer

C) $0.100	ext{ min}^{-1}$

Answer

D) $0.143	ext{ min}^{-1}$

Question 15

What are the dimensional formula parameters for Specific Heat Capacity ($c$)?

Accepted Answer

B) $[	ext{L}^2 	ext{T}^{-2} 	ext{K}^{-1}]$

Answer

A) $[	ext{M L}^2 	ext{T}^{-2} 	ext{K}^{-1}]$

Answer

C) $[	ext{M L T}^{-2} 	ext{K}^{-1}]$

Answer

D) $[	ext{L T}^{-2} 	ext{K}^{-1}]$

Question 16

At what temperature do the Celsius scale and Fahrenheit scale display the exact same numerical value?

Accepted Answer

A) $-40^\circ$

Answer

B) $0^\circ$

Answer

C) $40^\circ$

Answer

D) $100^\circ$

Question 17

The radiation peak of a star occurs at wavelength $\lambda_m = 500 ext{ nm}$. Using Wien's constant $b = 2.9 imes 10^{-3} ext{ m K}$, estimate the surface temperature of the star.

Accepted Answer

B) 5800 K

Answer

A) 2900 K

Answer

C) 7200 K

Answer

D) 11600 K

Question 18

An aluminum plate has an initial surface area of $4.0 m^2$ at $10^\circ ext{C}$. When heated to $60^\circ ext{C}$, what is the increase in area? ($\alpha_{ ext{Al}} = 2.5 imes 10^{-5} ext{ K}^{-1}$)

Accepted Answer

B) $0.010 m^2$

Answer

A) $0.005 m^2$

Answer

C) $0.020 m^2$

Answer

D) $0.040 m^2$

Question 19

How much heat energy is released when 0.25 kg of steam at $100^\circ ext{C}$ condenses into liquid water at $100^\circ ext{C}$? (Latent heat of vaporization $L_v = 2.26 imes 10^6 ext{ J/kg}$)

Accepted Answer

C) 565.0 kJ

Answer

A) 282.5 kJ

Answer

B) 452.0 kJ

Answer

D) 1130.0 kJ

Question 20

In a calorimetry experiment, 0.1 kg of an unknown metal block at $100^\circ ext{C}$ is dropped into 0.2 kg of water at $20^\circ ext{C}$. The final equilibrium temperature is $25^\circ ext{C}$.

Find the specific heat capacity of the metal, assuming negligible heat loss to the surroundings. ($c_{ ext{water}} = 4200 ext{ J kg}^{-1} ext{K}^{-1}$)

Accepted Answer

C) $560	ext{ J kg}^{-1}	ext{K}^{-1}$

Answer

A) $280	ext{ J kg}^{-1}	ext{K}^{-1}$

Answer

B) $420	ext{ J kg}^{-1}	ext{K}^{-1}$

Answer

D) $840	ext{ J kg}^{-1}	ext{K}^{-1}$

Set 5Grade 11 : Physics - Thermal Properties