The
refractive index of glass is 1.5. the speed of light in air is 3 x 108
m/s. What will be the speed of light in the glass?
A) 2 x 108 m/s
B) 3 x 1010 m/s
C) 2.5 x 1010 m/s
D) 3.3 x 103 m/s
Explanation: Step 1. Given data:
Speed of light in vacuum (c) = 3×108m/s
Speed of light in any medium = speed of light in vacuum. (Speed of light is independent of any medium or vacuum)
Hence, the speed of light in air (c) = 3×108 m/s
Refractive index of glass (ng) = 1.5
Step 2. Formula used:
Speed of light in a glass (v) = Speed of light in air (c) / Refractive index of glass (ng)
Step 3. Calculations:
As we know, Speed of light in a glass (v) = Speed of light in air (c) / Refractive index of glass (ng)
Or v=c/ ng =3×108/1.5=2×108m/s
Hence, the speed of light in glass will be 2×108m/s
A solution which can dissolve more solute a given temperature is called:
A) Saturated solution
B) Unsaturated solution
C) Super saturated solution
D) Standard solution
Explanation: A saturated solution is a solution that contains the maximum amount of solute that can be dissolved under the condition at which the solution exists.
The flame used in cutting and welding of metals is_________
A) Oxy-hydrogen flame
B) Polythene
C) 1,2-bomoethene
D) Ethylene
This will be the book you want.
[Choose the correct function of the model verb in this sentence]
A) Command
B) Suggestion
C) Assumption
D) Ability
Ali writes news reports.
[Choose the correct passive voice]
A) New reports is written by Ali.
B) News reports are being written by Ali.
C) News reports are being written by Ali.
D) News reports was written by Ali
اسلام سے پہلے بیوہ عورتوں کے لئے کتنا سوگ تھا؟
A) دو سال چار ماہ اور پندرہ دن
B) دس سال چار ماہ
C) پانچ سال چار ماہ اور دس دن
D) ایک سال
