Physics Questions And Answers 140-153

140. Radioactivity was discovered by_________?
 A. J.J. Thomson
 b.  W.Roentgen
 c.  H.Becquerel
 d.  None of these

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Ans. C H. Becquerel
Antoine-Henri Becquerel is known for his discovery of radioactivity, for which he received the Nobel Prize for Physics in 1903 Unstable atomic nuclei will spontaneously decompose to form nuclei with a higher stability. The decomposition process is called radioactivity.



141. Acceleration is _____
a. The speed at any given instant in time
b. The rate at which an object moves
c. The rate at which an object changes its velocity
d. None of the above

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ANSWER: c. The rate at which an object changes its velocity



142. When the electron of hydrogen atom jumps from any of the outer orbits to the first orbit, the series of spectral lines emitted is called
a. Balmer series
b. Paschen series
c. Brackett series
d. Lyman series

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ANSWER : : Lyman series



143. Water is a _____________ Conductor of electricity.  
A.  super conductor
B.  bad conductor
C.  speed conductor
D.  None of these

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Answer : B.  bad conductor




144. By which of the following methods does heat transfer not take place?   
a. Convection
b. Refraction Right!
c. Conduction
d. Radiation

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Answer : B


145. Which one of the following is an scalar quantity?
A.  Force
B.  Pressure
C.  Velocity
D.  Acceleration

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Answer : B.  Pressure


146. When a body moves with a constant speed in a circle?
a.   its acceleration is zero
b.   its acceleration is increasing
c.   its velocity is uniform
d.   its velocity is changing


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Answer : its velocity is changing



147. A thermometer for measuring very low temperature is called: 
a. pyrometer
b. bolometer
c. cryometer
d. platinum resistant thermometer

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Answer : c. cryometer


148.   Which Instrument is used to determine the intensity of colors?
A. Chronometer                               
B. Cathetometer              
C. Colorimeter                   
D. Commutator

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Ans. C




149. Newton's 1st Law is the law of -
1. Inertia
2. Force
3. Momentum
4. Acceleration

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Ans: 1



150. Name of the instrument to measure atomspheric pressure ?
a. Barometer
b. Barograph
c. Bolometer
d. Callipers

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Answer: Option A
Explanation:
Barograph - Recordings of atmospheric pressure,
Bolometer - Used to measure heat radiation,
Callipers - Used to measure inner and outer diameters of bodies.




151. Aviation fuel for Jet aeroplanes consists of purified  
A.  Petrol
B.  Kerosene
C.  Gasoline
D.  Diesel

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Answer : B.  Kerosene



152.  Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the 
transformer is due to
A. the heating effect of current alone
B. hysteresis loss alone
C. both the heating effect of current and hysteresis loss
D. intense sunlight at noon

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Answer: C




153. The base of an electric iron is brightly polished mainly
A) to make it smooth and frictionless
B) to make it rust-proof
C) to reduce heat loss by radiation
D) to make it more durable

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Answer: C) to reduce heat loss by radiation 
Explanation:
Polished surfaces are poor radiators of heat. So loss of heat on that account is reduced and the electric iron remains 
hotter than otherwise.



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Physics Questions And Answers - 126

126.Cooking taken longest time
a. the sea level
b. Simla
c. Mount Everest
d. None of these

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Ans. C
At Mount Everest
Everest is 8.848 kilometers tall, the highest elevation above sea level, the lower the air pressure.
That's because there's less air above you pushing down. When air pressure is lower, it's easier for water to boil--to change from liquid to gas. So as you go up a mountain, the temperature needed to make the water boil is lower. The other factor is that once water is boiling, it doesn't get any hotter. All the extra energy going into the boiling water is being used to change the liquid into gas.


127. What does Displacement refer to?
a. It refers to how much ground an object has covered
b. It refers to how far out of place an object is
c. It refers to how fast an object is moving
d. It refers to the rate at which an object changes its position

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ANSWER: b. It refers to how far out of place an object is


128. Name the barometer which does not contain a liquid: 
a. Aneroid barometer
b. Fortin's barometer
c. Mercury barometer
d. Barostat

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ANSWER: a. Aneroid barometer



128. Speed is _____
a. Scalar quantity which does not keep track of direction
b. Scalar quantity which keeps track of direction
c. Vector quantity which does not keep track of direction
d. None of above

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ANSWER: a. Scalar quantity which does not keep track of direction


129. Which of the following is similar to the solar system
a. Rutherford atom model
b. Dalton atom model
c. Thomson atom model
d. Prout atom model

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ANSWER : : Rutherford atom model


130. Zinc Oxide is  
A.  Acidic
B.  Basic
C.  Neutral
D.  Amphoteric

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Answer : D.  Amphoteric


131. Rate of change of displacement is called?
A. Speed                             
B. Work                                                
C. Force                                                
D. Velocity

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Answer. D


132. To correct his/her vision, a person suffering from short-sightedness will have to use -
1. Convex lens
2. Concave lens
3. Convex mirror
4. Bifocal Lens

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Ans: 2


133. Which instrument is used to measure depth of ocean ?
Galvanometer
Fluxmeter
Endoscope
Fathometer

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Answer: Option D


134.  What is the heaviest of the naturally occuring Noble gases?  
A.  Radon
B.  Xenon
C.  Helium
D.  Argon

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Answer : A.  Radon


135. Siphon will fail to work if
A. the densities of the liquid in the two vessels are equal
B. the level of the liquid in the two vessels are at the same height
C. both its limbs are of unequal length
D. the temperature of the liquids in the two vessels are the same

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Answer: B



136. Which one of the following remains constant while throwing a ball upward?  
A.  Displacement
B.  Kinectic energy
C.  Acceleration
D.  Velocity

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Answer : C.  Acceleration


137. In a freezer ice cubes will be formed more quickly in trays made of 
A. rubber
B. plastic
C. aluminium
D. wood

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Answer: C) aluminium 
Explanation:
Aluminium being a good conductor of heat conducts away the heat from the substance quite easily and causes quick freezing.



138. Which one of the following remains constant while throwing a ball upward?
A. velocity
B. displacement
C. acceleration
D. kinectic energy

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Answer: C. acceleration



139. A freely suspended magnet always aligns itself along the 
a. West South Axis
b. East West Axis
c. North South Axis 
d.East South Axis

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Answer: c. North South Axis


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Physics Questions And Answers

112.A wave under goes reflection from a rigid boundary. One of its characteristic parameters that changes is
a. Frequency 
b. phase 
c. velocity 
d. wavelength

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Answer: phase


113. What does this statement define 
The rate of change of position in a fixed direction.
a. Velocity 
b. Speed
c. Acceleration
d. Momentum

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Answer: a. Velocity 


114. Which one of the following is an scalar quantity?
A.  Force
B.  Pressure
C.  Velocity
D.  Acceleration

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Answer: B. Pressure



115. Vectors are the quantities that are described by ____
a. Both magnitude & direction
b. Velocity
c. Magnitude
d. Direction

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ANSWER: a. Both magnitude & direction



116. For ionizing an excited hydrogen atom, the energy required in eV will be
a  little less than 13.6 eV
b. 13.6 eV
c. more than 13.6 eV
d. 3.4 eV or loss

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ANSWER : : 3.4 eV or loss


117. Zinc Oxide is  
A.  Acidic
B.  Basic
C.  Neutral
D.  Amphoteric

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Answer : D.  Amphoteric



118. Rate of change of distance is called?
A. Force                               
B. Pressure                         
C. Velocity                           
D. Speed

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Ans. D


119. Tides are primarily a result of the -
a. Attraction of the moon
b. Farrel's Law
c. Ocean currents
d. Pressure system of the earth

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Ans: a



120. The absorption of ink by blotting paper involves
A. viscosity of ink
B. capillary action phenomenon
C. diffusion of ink through the blotting
D. siphon action

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Answer: B



121. Which Instrument is used to measure the power of electric circuit?
A. Volt meter                     
B. Barograph                      
C. Watt meter                   
D. Wave meter

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Ans. C


122. Power of a lens is measured in
A. ultrasonic unit
B. decibel
C. dioptre
D. magnification

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Answer: C. dioptre


123. Formation of shadows can be explained by 
A) rectilinear propagation of light
B) reflection
C) refraction
D) total internal reflection

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Answer: A) rectilinear propagation of light



124. Recoil of a gun is an example of  
A.  Conservation of mass
B.  conservation of energy
C.  conservationofPE into KE
D.  conservation of linear momentum

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Answer : D.  conservation of linear momentum



125. Conductors have a _______ resistance.   
a. High
b. Low 
c. Unknown
d. Intermediate

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Answer : b. Low

Physics Questions And Answers

99. Which one among the following radiations carries maximum energy?
A. gamma rays
B. x–rays
C. infra red rays
D. ultraviolet rays

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Answer: A. gamma rays


100. What is the rate of acceleration of gravity?
a. 10 m/s/s
b. 9.8 m/s/s
c. 6.8 m/s/s
d. 7.8 m/s/s

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ANSWER: b. 9.8 m/s/s


101. The wave number is the number?
a. of waves that cross in one second
b. associated with the orbit
c. of waves per unit length
d. of spectral lines produced

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ANSWER : of waves per unit length


102. Pure water freezes at what temperature?  
A.  47 F
B.  32 F
C.  0 F
D.  19 F

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Answer : B.  32 F



103. AC Voltage in our household circuit ____
A. 135V                                 
B. 220V                                 
C. 230V                                 
D. None of the above

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Ans. C


104. According to kinetic theory gases, at the temperature absolute zero, the gas molecules -
a. Start movement
b. Become massless
c. Start emitting light
d. Stop movement

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Ans: 4



105. It is easier to roll a stone up a sloping road than to lift it vertical upwards because
A. work done in rolling is more than in lifting
B. work done in lifting the stone is equal to rolling it
C. work done in both is same but the rate of doing work is less in rolling
D.work done in rolling a stone is less than in lifting it

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Answer: D


106. Which vitamin is abundant in citrus fruits?  
A.  Vitamin A
B.  Vitamin B
C.  Vitamin C
D.  Vitamin D

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Answer: C.  Vitamin C



107. X–rays travel with the velocity of
A. positive rays
B. sound
C. light
D. alpha rays

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Answer:  C. light



108. The working principle of a washing machine is
A) reverse osmosis
B) diffusion
C) centrifugation
D) dialysis

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Answer: C) centrifugation


109. What is the main constituent of coal gas?  
A.  Oxygen
B.  Water
C.  Nitrogen
D.  Methane

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Answer : D.  Methane



110. Which device controls heating and cooling to maintain a desired temperature? 
a. cryostat
b. thermostat
c. thermister
d. thermite

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Answer : Thermostat



111. Large angle produces?
a. curve trajectory
b. high trajectory
c. straight trajectory
d. flat trajectory

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Answer :  b. high trajectory

Physics Questions And Answers

85. An object is kept 5 cm in front of a concave mirror of focal length 15 cm. What will be the nature of the image ?
a. virtual, not magnified 
b. virtual, magnified 
c. real not magnified 
d. real magnified

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Answer: virtual, magnified


86. Which one is a scalar quantity?
a. Acceleration
b. Displacement
c. Speed
d. Velocity

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ANSWER: c.Speed


87. The total energy of an electron in any atom is
a. zero
b. negative
c. positive
d. infinite

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ANSWER : : negative


88. Which one of the following remains constant while throwing a ball upward?  
A.  Displacement
B.  Kinectic energy
C.  Acceleration
D.  Velocity

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Answer : C.  Acceleration


89. Which Instrument is used to measure depth of ocean?
A. Endoscope                    
B. Ammeter                       
C. Fathometer                   
D. Anemometer   
           
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Ans. C


90. The nuclear force is -
1. Short range repulsive force
2. Short range attractive force
3. Long range repulsive force
4. Long range attractive force

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Ans: 2


91. Who is the father of discoveries?
A. Edison
B. Pascal
C. Einstein
D. Archimedes

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Answer: D. Archimedes



92. The speed of light will be minimum while passing through
A. water
B. vaccum
C. air
D. glass

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Answer: D. glass



93. Which one among the following radiations carries maximum energy?  
A.  Ultraviolet rays
B.  Gamma rays
C.  X- rays
D.  Infra red rays

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Answer : B.  Gamma ray


94. The sunlight from sun to Earth reaches in -
A.  5 minutes
B.  6 minutes
C.  8 minutes
D.  10 minutes

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Answer : C.  8 minutes



95. What type of lens is a magnifying glass?   Add Question to Review List
a. Plano-Concave
b. Concave
c. Convex 
d. Plane Glass

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Answer: c. Convex 



96. To attain maximum range, the projectile must be launched at an angle of?
a.   90°
b.   45°
c.   0°
d.   60°

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Answer: b.   45°


97. What is the name of the instrument that measures and records the relative humidity of the air ? 
a. hygroscope
b. hygrograph
c. hygrometer
d. hygrister

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Answer: c. hygrometer




98.How can boilng point of a liquid be reduced ? 
a. by adding a solid of lower melting point 
b. by dissolving a soluble solid in it 
c. by increasing the pressure on the liquid d.by decreasing the pressure on the liquid

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Answer: by decreasing the pressure on the liquid



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