SSC CGL PHYSICS Question Answer Part - 3 (Q. No. 101-150)
101. A glass container cracks when very hot tea is poured into it. A probable reason for this is the
(a) low thermal conductivity of glass
(b) high thermal conductivity of glass
(c) low specific heat of glass
(d) none of these
102. Which is the fastest mode of heat loss?
(a) Conduction
(b) convection
(c) radiation
(d) all are equally fast
103. The clouds float in the atmosphere because of their low
(a) temperature
(b) velocity
(c) pressure
(d) density
104. What is the principle by which a cooling system (Radiator) in a motor car works?
(a) Conduction only
(b) Convection
(c) Radiation only
(d) Both conduction and radiation
105. How can boiling 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
106. At normal temperature, due to a puncture, the compressed air inside the tube of a car wheel suddenly starts coming out. Then the air inside the tube
(a) starts becoming hotter
(b) starts becoming cooler
(c) Remains at the same temperature
(d) May become hotter or cooler depending on the amount of water vapour present in the air.
107. Clothes keep us warm in winter because they
(a) Supply heat
(b) do not radiat heat
(c) Prevent air from contacting the body
(d) prevent the heat of the boyd from excaping
108. The bset conductor of heat among the following is-
(a) Alcohol
(b) Mercury
(c) Ether
(d) Water
109. Metal tea pots have wooden handles because
(a) Wood is a bad conductor of heat
(b) it prevents electric shock
(c) its gives beauty to the pots
(d) it is hygienic
110. White clothes are cooler than black ones because they
(a) Absorb all the light tha reaches them
(b) reflect all the light that reaches them
(c) will nt allow the light to penetrate
(d) cool the sun light completely
111. An instrument used to measure humidity is
(a) anemometer
(b) hygrometer
(c) thermomenter
(d) pyrheliometer
112. The temperature of water at the bottom of a waterfall is higher than that at the top because
(a) Water at the bottom has greater potential energy
(b) The surface at the bottom provides heat
(c) Kinetic energy of falling water is converted into heat
(d) falling water absorbs heat from the surroundings
113. The temperature of boiling water in a steam engine may be high because:
(a) there are dissolved substances in water
(b) there is low pressure inside the boiler
(c) there is high pressure inside the boiler
(d) the fire is at very high temperature
114. A reversible and an irreversible engine are working between the same limits of temperature. The efficiency of
(a) the reversible engine is greater that the irreversible engine
(b) each engine is 100%
(c) the two engine are equal
(d) the irreversible engine is greater than the reversible engine
115. Perspiration cools the body because
(a) Presence of water on the skin is cooling
(b) Evaporation requires latent heat
(c) Water has a high specific heat
(d) Water is poor conductor of heat
116. Burns caused by steam are much more severe than those caused by boiling water because
(a) steam has latent heat
(b) Steam is gas and engulfs the body quickly
(c) Stem pierces throught the pores of body quickly
(d) Temperature of steam is higher
117. Ice is packed in saw dust because
(a) sa dust does not stikc to the ice
(b) saw dust will not get melted easily
(c) saw dust is poor conductor of heat
(d) saw dust is a good conductor of heat
118. The lowest temperature is recorded by
(a) Mercurial thermometer
(b) Minimum reading thermometer
(c) Alcohol thermometer
(d) Maximum reading thermometer
119. The length of the pendulum is doubled and the mass of its bob is halved. Its time sperod would
(a) become double
(b) become half
(c) become √2 times
(d) remain the same
120. Sound waves are similar to the waves
(a) of laswer light passing through air
(b) generated in a stretched wire by hitting or plucking the wire
(c) generated in a pipe filled with air by moving the piston attached to the pipe up and down
(d) generated by the mobile phone towers
121. Sound travel fastest in
(a) steel
(b) air
(c) water
(d) vaccum
122. With the rise of temperature, the speed of sound in a gas
(a) Increases
(b) decreases
(c) remains the same
(d) none of these
123. The quality of sound produced by an instrument depends on the
(a) frequency
(b) intensity
(c) number of overtones
(d) none of these
124. Instrument used to study the behavior of a vibrating string is:
(a) Hygrometer
(b) Sonmeter
(c) Barometer
(d) Hydrometer
125. The Doppler’s effect is applicable for
(a) light wave
(b) sound wave
(c) space wave
(d) both (a) and (b)
126. When we hear a sound, we can identify its source from
(a) wave length of sound
(b) the overtones present in the sound
(c) the intensity of sound
(d) the amplitude of sound
127. Velocity of sound in air
(i) increases with temperature
(ii) decreases with temperature
(iii) increase with pressure
(iv) is independent of pressure
(v) is independent of temperature
(a) Only (i) and (ii) are true
(b) Only (ii) and (iv) are true
(c) Only (i) and (iii) are true
(d) Only (i) and (iv) are true
128. Beats occure because of
(a) Interference
(b) reflection
(c) refraction
(d) Doppler effect
129. With the increase in temperature, frequency of the sound from on organ pipe
(a) decreases
(b) increases
(c) remain unchanged
(d) changes erractically
130. Sound waves do not exhibit the phenomenon of
(a) interference
(b) diffraction
(c) refraction
(d) polarization
131. Quality of musical note depends on
(a) fundamental frequency
(b) harmonics present
(c) amplitude of the wave
(d) velocity of sound in medium
132. The loudness of sound depends upon
(a) velocity
(b) pitch
(c) amplitude
(d) wavelength
133. When light waves pass from air to glass, the variables affected are
(a) wavelength, frequency and velocity
(b) velocity and frequency
(c) wavelength and frequency
(d) wavelength and velocity
134. Why is sound heard with more intensity through CO2 than through the air?
(a) density of CO2 is more than that of air
(b) density of CO2 is less than that of air
(c) air is a bad conductor of heat
(d) CO2 is a compound, but air is a mixture of gases.
135. X – rays are used for the study of crystal structure because
(a) X- rays are completely absorbed by the crystal
(b) The wavelength of X – rays is of the same order of magnitude as the interatomic spacing in crystals
(c) The wavelength of X – rays is very small in comparison with the interatomic spacing in crystals
(d) The crystals are completely transparent to X – rays
136. The audible requency range of human ear is
(a) 20 hertz to 200 hertz
(b) 2 hertz to 20 hertz
(c) 200 hertz to 2000 hertz
(d) 20 hertz to 20000 hertz
137. How does time period (T) of a seconds pendulum very with length (l) ?
(a) T ∝ √𦐠(b) T ∝ l2
(c) T ∝ l
(d) T does not depend on l
138. Sound moves with higher velocity if
(a) pressure of the medium is decreased
(b) temperature of the medium in increased
(c) humidity of the medium
(d) both (b) and (c)
139. The ozone layer absorbs
(a) infrared radiation
(b) ultraviolet radiation
(c) X – rays
(d) gamma – rays
140. Which are the relevant waves in telecommunication?
(a) X – rays
(b) Violet – rays
(c) microwaves
(d) all of them
141. Which of the following electromagnetic waves has the longest wavelength?
(a) infrared rays
(b) gamma rays
(c) light rays
(d) ultraviolet rays
142. X- rays were discovered by-
(a) Roentgen
(b) Becquere
(c) Curie
(d) Van lane
143. Consider the following electromagnetic waves
1. X- rays 2. gamma Rays
3. Microwaves 4. Radio waves
What is the correct sequence in the order of their increasing energy?
(a) 4, 3, 1 and 2
(b) 1, 3, 2 and 4
(c) 4, 2, 1 and 3
(d) 1, 4, 3 and 2
144. In which of the following sequences are the electromagnetic radiations in decreasing order of wave lengths
(a) infrared, radio, X –rays, visible
(b) radio, infrared, visible, X – rays
(c) radio, visible, infrared, X – rays
(d) X – rays, visible, infrared, radio
145. Which one of the following pairs of rays is electromagnetic in nature –
(a) beta rays and gamma rays
(b) cathode rays and X – rays
(c) alfa rays and beta – rays
(d) X rays and gamma rays
146. When X – rays are produced, then
(a) heat is produced on the target
(b) heat is observed by the target
(c) Temperature of the target is being constent
(d) a lumineous light is to be seen on the target
147. The waves used in sonography are -
(a) Micro waves
(b) Infra – red waves
(c) Sound waves
(d) Ultrasonic waves
148. Cosmic rays
(a) are charged particles
(b) are uncharged particles
(c) can be charged as well as unchanged
(d) None of the above
149. Decibel is the unit used for measuring
(a) Speed of light
(b) Intensity of heat
(c) Intensity of sound
(d) Radiowave frequency
150. The sounds having frequency of 20 Hz to 20, 000 Hz are
(a) Ultrasound
(b) Infrasonic
(c) Hydpersonic
(d) Audible sounds
Answer Key
