Q.1:- Compared to burn due to air at 100°C, a burn due to steam at 100°C is ?
Ans:- More Dangerous
Q.2:- When a CD (compact disc used in audio and video systems) is seen in sunlight, rainbow like colours are seen. This can be explained on the basis of the phenomenon of ?
Ans: Refraction, Diffraction and Transmission
Q.3:- Evening Sun is not as hot as the mid day sun. What is the reason ?
Ans:- In the evening, radiations travels larger distance through atmosphere
Q.4:- A bucket full of water is kept in a room and it cools from 75°C to 70°C in time T1 minutes, from 70°C to 65°C in timeT2 minutes, and from 65°C to 60°C in time T3 minutes, then ?
Ans:- T1 < T2 < T3
Q.5:- The sprinkling of water slightly reduces the temperature of a closed room because ?
Ans:- Water has large latent heat of vaporization
Q.6:- A myopic eye can be corrected by using a ?
Ans:- Concave Lens
Q.7:- A dynamo which is said to generate electricity actually acts as a ?
Ans:- Converter of energy
Q.8:- The cooling by a desert cooler is based on ?
Ans:- Hot air replacement
Q.9:- Optical fibre works on the principle of ?
Ans:- Total Internal Reflection
Q.10:- Give the name of the instrument that is used to measure blood pressure ?
Ans:- Sphygmomanometer
Q.11:- The colour of light is determined by its ?
Ans:- Wavelength
Q.12:- Laser is a device for producing ?
Ans:- Stimulated Radiation
Q.13:- Transformer is used ?
Ans:- To step up or step down AC voltages
Q.14:- If the doors of a refrigerator are left open for a few hours, the room temperature will ?
Ans:- Increase
Q.15:- Butter paper is an example of …………. object.
Ans:- A Translucent
Q.16:- To hear a clear echo, the minimum distance should be ?
Ans:- 16.5 meter
Q.17:- China wares are wraped in straw of paper before packing. This is the application of concept of ?
Ans:- Impulse
Q.18:- One feels heavier in a lift when the lift ?
Ans:- Just begins to go up
Q.19:- Tube light is filled with ?
Ans:- Mercuric oxide and argon gas
Q.20:- The mirror used by a dentist to examine the teeth of patients is ?
Ans:- Concave
Q.21:- Richter scale is used for measuring ?
Ans:- Amplitude of seismic waves
Q.22:- The sun is seen before the actual sun rise because of …………
Ans:- Refraction
Q.23:- When a body is stationary, then ?
Ans:- The net forces acting on it balances each other
Q.24:- CT scan is done by using ?
Ans:- X-Rays
Q.25:- Which mirror is used as a rear view mirror in the vehicles ?
Ans:- Convex
