THERMO AND ELECTROMAG Flashcards
- The unit of temperature in S.I. units is
a. Centigrade
b. Celsius
c. Fahrenheit
d. Kelvin
d. Kelvin
- A closed system is one in which
a. mass does not cross boundaries of the system, though energy may do so
b. mass crosses the boundary but not the energy
c. neither mass nor energy crosses the boundaries of the system
d. both energy and mass cross the boundaries of the system
a. mass does not cross boundaries of the system, though energy may do so
- Temperature of a gas is produced due to
a. its heating value
b. kinetic energy of molecules
c. repulsion of molecules
d. attraction of molecules
b. kinetic energy of molecules
- A solid object with a specific density of less than 1 will
a. Float on liquid water.
b. Mixed evenly and stay mixed with liquid water.
c. Sink in liquid water.
d. Dissolve in liquid water.
a. Float on liquid water.
- Diffusion of gases at room temperature occurs because
a. There are no many atoms per unit volume.
b. The atoms or molecules move rapidly.
c. Gases always have high specific gravity.
d. Gases dissolve easily in one another.
b. The atoms or molecules move rapidly.
A decrease in temperature can cause a gas to
a. Boil away into vapor.
b. Turn into a liquid.
c. Exert increased pressure in a rigid container.
d. Turn to ice
b. Turn into a liquid.
- The heat of fusion of a substance refers to
a. The temperature necessary to produce a nuclear fusion reaction.
b. The heat required to liquefy a vapor at its condensation temperature.
c. The heat required to liquefy a solid at its melting temperature.
d. The temperature at which a liquid becomes a gas.
c. The heat required to liquefy a solid at its melting temperature.
- One gram of ice at 0°C is placed on a container containing two million cubic meters of water at 0°C. Assuming no heat loss, what will happen?
a. ice will become water
b. some part of ice will not change
c. the volume of ice will not change
d. all of the above
c. the volume of ice will not change
- Absolute zero temperature is
a. 32°F
b. 4°C
c. 0°C
d. 0°K
d. 0°K
- What temperature readings do the Fahrenheit and Celsius scales have the same value?
a. -30
b. -35
c. -40
d. -45
c. -40
- Indicate the FALSE statement about temperature.
a. Boiling point of centigrade scale is 100
b. Fahrenheit scale was invented by a German
c. Absolute temperature scale is expressed in 0K
d. absolute zero in Fahrenheit scale is -273
d. absolute zero in Fahrenheit scale is -273
- The kinetic energy of the atoms and molecules due to their random motion is called
a. thermal energy
b. elastic potential energy
c. rest energy
d. heat energy
a. thermal energy
- The same volume of all gases would represent their
a. densities
b. specific weights
c. molecular weights
d. gas characteristic constants
c. molecular weights
- An open system is one in which
a. mass does not cross boundaries of the system, though energy may do so
b. neither mass nor energy crosses the boundaries of the system
c. both energy and mass cross the boundaries of the system
d. mass crosses the boundary but not the energy
c. both energy and mass cross the boundaries of the system
- Calorie is a measure of
a. Specific heat
b. Quantity of heat
c. Thermal capacity
d. Entropy
b. Quantity of heat
- The statement which correctly represents Ohm’s law:
a. V = IR
b. V = R/I
c. R = VI
d. I = R/V
a. V = IR
- Unit of voltage is:
a. Volt
b. Watt
c. Coulomb
d. Amper
a. Volt
Unit of current is:
a. Volt
b. Watt
c. Coulomb
d. Ampere
d. Ampere
- Unit of power is:
a. Volt
b. Watt
c. Coulomb
d. Ampere
b. Watt
- Unit of resistance is:
a. Volt
b. Watt
c. Ohms
d. Ampere
c. Ohms
- Components which obey Ohm’s law are known as:
a. Resistors
b. Ohmic components
c. Non-ohmic components
d. None of these
b. Ohmic components
- Ohmic components have a __________ V-I curve:
a. Straight line VI curve
b. Parabolic VI curve
c. Non-linear VI curve
d. Sinusoidal VI curve
a. Straight line VI curve
- Coulomb is the unit of which quantity?
a. Field strength
b. Charge
c. Permittivity
d. Force
b. Charge
- Coulomb law is employed in
a. Electrostatics
b. Magnetostatics
c. Electromagnetics
d. Maxwell theory
a. Electrostatics
Coulomb’s law is only true for point charges whose sizes are
a. medium
b. very large
c. very small
d. large
c. very small
As per Coulomb’s law, the force of attraction or repulsion between two point charges is directly proportional to the
a. sum of the magnitude of charges
b. square of the distance between them
c. product of the magnitude of charges
d. cube of the distance
c. product of the magnitude of charges
- The value of k in coulomb’s law depends upon
a. magnitude of charges
b. distance between charges
c. medium between two charges
d. all of above
c. medium between two charges
- When electric current is passed, electrons move from:
a. high potential to low potential.
b. low potential to high potential.
c. in the direction of the current.
d. against the direction of the current.
b. low potential to high potential.
- The heating element of an electric iron is made up of:
a. Copper
b. Nichrome
c. Aluminium
d. iron
b. Nichrome
- The electrical resistance of insulators is
a. High
b. Low
c. Zero
d. infinitely high
d. infinitely high
- Electric potential is a:
a. scalar quantity
b. vector quantity
c. neither scalar nor vector
d. sometimes scalar and sometimes vector
a. scalar quantity
Which among the following statements is true with regard to electric field lines?
a. Electric field lines always intersect
b. Electric field lines may or may not intersect
c. Electric field lines can be seen
d. Electric field lines never intersect
d. Electric field lines never intersect
Which, among the following, is the field where electric charge experiences a force?
a. Electric field
b. Magnetic field
c. Gravitational field
d. Electric, magnetic and gravitational field
a. Electric field
- What happens when one material is rubbed against another?
a. The material becomes electrically neutral
b. The material becomes electrically charged
c. The material becomes negatively charged
d. The material becomes positively charged
b. The material becomes electrically charged
- The substances which have a large number of free electrons and offer a low resistance are called
a. insulators
b. inductors
c. semi-conductors
d. conductors
d. conductors
