CTET Solved Paper - CTET September 2015
121. Which one of the following is not a conductor of electricity?
- Option : B
- Explanation : (B) Distilled water is not electrolyte i.e. it does not capable to furnish ions in its solution and does not current flows due to motion of ions. While salt water, vinegar and lime juice are electrolyte and they are made up of ions and flow current in liquid or fused state.
122. Medium A is optically denser than Medium B. Which one of the following statements is true?
- Option : D
- Explanation : (D) The speed of light is less in the optically dense medium because these are more atoms in the dense medium to obstruct the path of the light. Light is an electromagnetic wave and its speed depends upon the optical density of the medium. As the density of the medium increases, the speed of the light wave decreases.
123. We are not crushed under the weight of atmosphere, because
- A
the pressure inside our body is less than atmospheric pressure
- B
the pressure inside our body is equal to the atmospheric pressure and cancels the pressure from outside
- C
the pressure inside our body is more than atmospheric pressure
- D
the pressure inside our body is more than atmospheric pressure and cancels the pressure from outside
- Option : B
- Explanation : (B) The weight of atmosphere does not crush our body because we posses an internal pressure due to the presence of different materials and fluids inside our body. This internal pressure cancels out the external pressure of the atmosphere.
124. A block of iron dropped in a vessel of water, sinks to the bottom. This is because
- Option : D
- Explanation : (D) According to law of flotation, a body floats on the surface of liquid, if the weight of liquid displaced by the body is equals to the weight of the body. On the other hand, a body sinks if weight of liquid displaced by it is less than its own weight.
125. Which one of the following statements is incorrect?
- A
Generally the voice of a man is shriller than that of a woman
- B
A bird makes a high pitched sound whereas a lion makes a low pitched roar
- C
A drum vibrates with a low frequency, therefore it produces a low pitched sound
- D
A whistle has a high frequency and therefore it produces a sound of higher pitch
- Option : A
- Explanation : (A) The shrillness of a sound depends upon its frequency and pitch, the higher the pitch the shriller the sound. As the sound produced by the vocal chords of women is naturally higher than men. So, the sounds produced from the voices of women are shriller than men.
