Which temperature scale is considered most suited for scientific purposes?

• A) Kelvin.
• B) Fahrenheit.
• C) Centigrade.
• D) Absolute zero.

The relation for converting the temperature scale from Celsius to Fahrenheit is:

• A) $T_F = {9\over5} × T_C +32$
• B) $T_C = {5\over9} × (T_F-32)$
• C) $T_F = T_C − 273.15$
• D) $T_C = T_F + 273.15$

If you have a convex spherical mirror with silvering on its outside surface, how will the radius of curvature be defined?

• A) Zero
• B) Undefined
• C) Negative
• D) Positive

All-natural process proceeds towards a state of:

• A) Remains constant
• B) Increase in entropy
• C) Decrease in entropy
• D) None of these

In the constant volume gas thermometer, what is the role of the tube on the right side?

• A) It measures the pressure.
• B) It changes the gas composition.
• C) It keeps the reference level fixed.
• D) It determines the gas volume.

Fiber optics works on the principle of _____________.

• A) Fermat's principle
• B) Snell's law
• C) Young's principle
• D) Total internal reflection

Total internal reflection is possible when a light ray travels from:

• A) Air to glass
• B) Air to water
• C) Glass to water
• D) Water to glass

A virtual image is one:

• A) from which light rays diverge as they pass through
• B) toward which light rays converge but do not pass through
• C) from which light rays diverge but do not pass through
• D) toward which light rays converge and pass through

When an iron rod is heated, the colors at different temperatures are noted. Which of the following colors shows that the iron rod is at the lowest temperature?

• A) Orrange
• B) Blue
• C) Red
• D) White

An erect object is in front of a convex mirror a distance greater than the focal length. The image is:

• A) Real, inverted, and larger than the object
• B) Virtual, erect, and smaller than the object
• C) Real, inverted, and smaller than the object
• D) Virtual, inverted, and larger than the object

According to special relativity, the speed of light is:

• A) Infinite
• B) Variable based on the observer's motion
• C) Always constant
• D) Zero

In Young’s double slit experiment, the position of the bright fringe is given by:

• A) Ym = mλd/L
• B) Ym = mLd/λ
• C) Ym = mL/λd
• D) Ym = mLλ/d

When an object (iron/tungsten) is heated, it emits light. It emits infrared (IR) light when it is heated at a temperature __________.

• A) above 2500 degree C
• B) Between 800 degree C to 1600 degree C
• C) Between 1600 degree C to 2500 degree C
• D) Below 800 degree C

Emission of electron by metals on heating is called:

• A) Compton emission
• B) Photoelectric emission
• C) Secondary emission
• D) Thermionic emission

A gas which strictly obeys the gas laws under all conditions of temperature and pressure is called:

• A) Ideal gas
• B) Inert gas
• C) Real gas
• D) Simple gas

Evidence that molecules of a gas are in constant motion is:

• A) Two gases interdi?use quickly
• B) Gases area easily compressed
• C) Warm air rises
• D) Winds exert pressure

What happens if a point source is placed at the focus of a convex lens?

• A) Rays reflect back
• B) Rays scatter
• C) Parallel beam emerges
• D) Rays converge to a point

Net change in entropy of a system in a Carnot cycle is:

• A) Zero
• B) Negative
• C) One
• D) Positive

A thermometer indicates 98.6?C.It may be:

• A) In a cup of hot tea
• B) Outdoors on ac old day
• C) In a normal person’s mouth
• D) In a comfortable room

Which of the following is NOT TRUE about index of refraction?

• A) Its value ranges from 0.1 – 1.9
• B) For glass its value is 1.5
• C) It has no units
• D) It is a ratio between speeds