Machine Gun was invented by Richard Gatling of USA in 1861,
Microscope was invented by Z. Jansen of Netherlands in 1590,
Motorcycle was invented by Edward Butler of England in 1884.
2. The force which opposes the relative motion between different layers of liquid or gases is called
Critical Velocity
Streamline Flow
Terminal Velocity
Viscous Force
Answer: Option D
Explanation:
Critical Velocity - The maximum velocity upto which fluid motion is streamline is called Critical Velocity.
Streamline Flow - If velocity of all fluid particles is same all the time then it can be said in streamline flow.
Terminal Velocity - When a body falls in viscous medium, its velocity first increases and finally becomes constant. The constant velocity is called terminal velocity.
3. What is refractive index ?
it is defined as the ratio of speed of light in the medium to the speed of light in vacuum.
it is defined as the ratio of speed of light in vacuum to the speed of light in the medium .
it is defined as the product of speed of light in medium and in vacuum.
None of above
Answer: Option B
4. The angle of reflection is equal to the angle of incidence.
True
False
Answer: Option A
5. The incident ray, reflected ray and normal to the reflecting surface at the incident point all never lie in same plane.