# MCQ in Physics Part 8 | ECE Board Exam

(Last Updated On: July 17, 2021) This is the Multiples Choice Questions Part 8 of the Series in Physics as one of the General Engineering and Applied Sciences (GEAS) topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including past Board Questions in General Engineering and Applied Sciences (GEAS), Physics Books, Journals and other Physics References.

#### Continue Practice Exam Test Questions Part 8 of the Series

Choose the letter of the best answer in each questions.

351. “At any point along a streamline in an ideal fluid in steady flow, the sum of the pressure, the potential energy per unit volume and the kinetic energy per unit volume have the same value.” The concept is known as

A. Bernoulli’s Energy Principles

B. Fluid theorem

C. Pascal’s theorem

D. Hydraulic theorem

Explanation:

352. The work done by all forces except the gravitational force is always equal to the one of the system.

A. Total mechanical energy

B. Total potential energy

C. Total kinetic energy

D. Total momentum

Explanation:

353. When the two waves of the same frequency, speed and amplitude traveling in opposite directions are superimposed,

A. the phase difference is always zero

B. distractive waves are produced

C. standing waves are produced

D. constructive interference always results to zero

Explanation:

354. According to this law, “The force between two charges varies directly as the magnitude of each charge and inversely as the square of the distance between them.”

A. Law of Universal Gravitation

B. Newton’s Law

C. Inverse Square Law

D. Coulomb’s Law

Explanation:

355. It describes the luminous flux incidence per unit area and is expressed in lumens per square meter.

A. Illuminance

B. Luminance

C. Luminous Intensity

Explanation:

356. The fluid pressure is the same in all directions. This is known as

A. Pascal’s Principle

B. Bernoulli’s Theorem

C. Ideal Fluid Principle

D. Archimedes Principle

Explanation:

357. The amount of heat needed to change solid to liquid is

A. condensation

B. cold fusion

C. latent heat of fusion

D. solid fusion

Explanation:

358. At the boiling point of liquid, the vapor pressure

A. is equal to external pressure on the surface of the liquid

B. is greater than the atmospheric pressure

C. is less than the atmospheric pressure

D. can have any value

Explanation:

359. Which of the following thermometers is best suited for measuring a temperature of nearly 1500°C?

A. Gas thermometer

B. Platinum resistance thermometer

C. Thermocouple thermometer

D. Mercury thermometer

Explanation:

360. The energy stored in a starched elastic material such as spring is

A. Mechanical energy

B. Elastic potential energy

C. Internal energy

D. Kinetic energy

Explanation:

361. In physics, if LF and LV are the latent heat of fusion and vaporization, respectively, which of the following equations apply in determining the amount of energy needed to freeze a liquid?

A. Q = -mif

B. Q = -miv

C. Q = mif

D. Q = miv

Explanation:

362. Which of the following is true? The density of water

A. Is maximum at 4°C

B. Decreases as the temperature is increased

C. Is minimum at 4°C

D. Increases with temperature

Explanation:

363. When the pitch of a note is raised then, its

A. frequency decreases

B. wavelength is increased

C. frequency increases

D. None of the above is true

Explanation:

364. Cohesion is the attraction between like

A. atom

B. element

C. compound

D. molecule

Explanation:

365. The quality known as specific heat is based on:

A. the increase in temperature due to induction

B. the heat needed for one pound of water to boil

C. the heat needed to increase the temperature to one gram of a substance one degree Celsius

D. the amount of heat required to melt one kg of lead

Explanation:

366. On decreasing the pressure, the boiling point of water will

A. increase

B. remain unaffected

C. decrease

D. may increase/decrease depending on the pressure

Explanation:

367. When sugar is added to water, its boiling point

A. increases

B. remains unaffected

C. decreases

D. Any of the above is possible

Explanation:

368. Which one of the following processes of heat transfer requires the presence of a fluid?

A. conduction

B. convection

D. none of these

Explanation:

369. When salt is added to water, its boiling point

A. increases

B. decreases

C. remains unaffected

D. may increase/decrease depending on the pressure

Explanation:

370. Which one of the following propagates with the same speed as speed of light?

A. The sound waves

B. The heat waves

C. The shock waves

D. The Beta rays

Explanation:

371. Which of the following is not true about sound waves?

A. They transmit the energy

B. They are propagated as a series of compressions and the rare fractions

C. They travel faster in air than in solids

D. They produce interference

Explanation:

372. Sound waves in air are

A. longitudinal

B. neither longitudinal nor transverse

C. transverse

D. stationary

Explanation:

373. Normal range of the frequency of sound, which the human beings can hear, is

A. Less than 20 Hz

B. More than 25,000 Hz

C. 20 Hz to 20,000 Hz

D. All of these

Explanation:

374. The loudness of sound depends upon its

A. Wavelength

B. Frequency

C. Amplitude

D. All of these

Explanation:

375. Sound above the frequency of 20,000 Hz is called

A. Supersonic sound

B. Intrasonic sound

C. Hypersonic sound

D. Ultrasonic sound

Explanation:

376. The surface of the thermos flask is silvered for minimizing heat transfer by what process?

A. conduction

C. convection

D. vaporization

Explanation:

377. Water starts boiling when

A. Its temperature reaches 100°C

B. Its vapor pressure equals 76 cm of mercury

C. Its saturated vapor pressure equals the external pressure on its surface

D. Its saturated vapor pressure is less than the atmospheric pressure

Explanation:

378. 500 gm of water at 4°C occupies a certain volume V. Which of the following statements is correct?

A. It will weigh less than one pound of water at 0°C

B. It will weigh more than 500 gm of water at 0°C

C. Its volume will decrease when its temperature is lowered

D. Its volume will increase when its temperature is lowered or raised

Explanation:

379. Heat will flow from one body to another in thermal contact with it, when they differ in

A. mass

B. specific mass

C. density

D. temperature

Explanation:

380. The amount of heat which is absorbed during the change of state of a substance without rise in its temperature is called its

A. Specific heat

B. Latent heat

C. Thermal conductivity

D. Water equivalent

Explanation:

381. The scientist who systematically demonstrated the equivalence of mechanical energy and heat was

A. Joule

B. Boltzmann

D. Kelvin

Explanation:

382. On a sunny day at the beach, the sand gets so hot and the water stays relatively cool is due to the difference in of water and sand.

A. density

B. specific heat

C. depth

D. thermal conductivity

Explanation:

383. The instrument, which measures temperature by radiation, is called

A. thermopile

B. thermometer

C. pyrometer

D. hydrometer

Explanation:

384. When the temperature of an ideal gas is increased at constant pressure,

A. the potential energy of molecules increases

B. the potential energy of molecules decreases

C. the kinetic energy of molecules increases

D. the kinetic energy of molecules decreases

Explanation:

385. The root mean square speed of the molecules of a gas is

A. independent of its pressure P

B. directly proportional to square root of P

C. directly proportional to the square of its temperature T

D. proportional to T

Explanation:

386. At what temperature do both the centigrade and Fahrenheit thermometers show the same reading?

A. -38°C

B. -40°C

C. -42°C

D. -50°C

Explanation:

387. A mercury thermometer is constructed at

A. room temperature

B. a temperature higher than the maximum range of the thermometer

C. a temperature lower than the minimum range of the thermometer

D. atmospheric pressure

Explanation:

388. The boiling point of water on plains is 100°C. At hills it will be

A. 100oC

B. Less than 100°C

C. More than 100°C

D. May be any of these

Explanation:

389. It is hotter over the top of a fire than at the same distance on the sides because of:

A. convection of heat

B. conduction of heat

D. convection, conduction and radiation of heat

Explanation:

390. The density of water is

A. same at all temperature

B. maximum at 4°C

C. minimum at 4°C

D. maximum at 0°C

Explanation:

391. When a substance is heated, its

A. molecules move more slowly

B. molecules move more rapidly

C. there is no change in the speed of its molecules

D. its temperature always increases

Explanation:

392. When common salt is sprinkled on ice the temperature of ice

A. increases

B. decreases

C. remains unchanged

D. none of these

Explanation:

393. The minimum temperature which can be measured with a mercury thermometer is

A. 0°C

B. -273°C

C. -39°C

D. -143°C

Explanation:

394. A wave in which the particles of the material move up and down as the waves goes from left is called a

A. Longitudinal wave

B. Transverse wave

C. Standing wave

D. None of these

Explanation:

395. When waves go from one place to another they transport

A. Energy and matter

B. Wavelength and matter

C. Frequency only

D. Energy only

Explanation:

396. The phenomenon of damping results in decrease in

A. frequency

B. velocity

C. wavelength

D. amplitude

Explanation:

397. Echo is formed as a result of

A. refraction of sound

B. diffraction of sound

C. interference of sound

D. reflection of sound

Explanation:

398. The characteristic of sound which enables us to distinguish two musical notes having the same frequency and loudness is called

A. pitch

B. intensity

C. timber

D. decibel

Explanation:

399. Which of the following could be a longitudinal wave?

A. electromagnetic waves

B. a sound wave in air

C. a water wave

D. waves on vibrating string

Explanation:

400. A Decibel is a

A. musical instrument

B. highest frequency emitted by a tuning fork

C. a measure of intensity level

D. a measure of clarity of sound

Explanation:

#### Online Questions and Answers in Physics Series

Following is the list of practice exam test questions in this brand new series:

College Physics MCQs
PART 1: MCQ from Number 1 – 50                        Answer key: PART 1
PART 2: MCQ from Number 51 – 100                   Answer key: PART 2
PART 3: MCQ from Number 101 – 150                 Answer key: PART 3
PART 4: MCQ from Number 151 – 200                 Answer key: PART 4
PART 5: MCQ from Number 201 – 250                 Answer key: PART 5
PART 6: MCQ from Number 251 – 300                 Answer key: PART 6
PART 7: MCQ from Number 301 – 350                 Answer key: PART 7
PART 8: MCQ from Number 351 – 400                 Answer key: PART 8
PART 9: MCQ from Number 401 – 450                 Answer key: PART 9
PART 10: MCQ from Number 451 – 500                 Answer key: PART 10

Complete List of MCQs in General Engineering and Applied Science per topic

Series of MCQ in General Engineering and Applied Science