Answer: A medium in which speed of light is more is known as optically rarer medium and a medium in which speed of light is less is said to be optically denser medium. For example in air and water, air is raer and water is a denser medium.
Explanation:
To solve this problem we will apply the concepts related to Reyleigh's criteria. Here the resolution of the eye is defined as 1.22 times the wavelength over the diameter of the eye. Mathematically this is,

Here,
D is diameter of the eye


The angle that relates the distance between the lights and the distance to the lamp is given by,

For small angle, 
Here,
d = Distance between lights
L = Distance from eye to lamp
For small angle 
Therefore,



Therefore the distance is 5.367km.
Answer:
10.4mm
Explanation:
2 pages = 1 leaf
200 pages = 100 leaves
100 × 0.10 = 10 mm thickness
Total thickness = 2(0.20) +10 = 0.4+10 = 10.4mm
Answer: The correct answer is B
Explanation: The string is pulling right and the string is unraveling causing it to accelerate left
Answer: rotational force
Explanation:
Torque is the twisting force which cause rotation and the axis of rotation is the point at which the object rotates.
Torque is a rotational force as it leads to the rotation of an object about an axis. Force simply means a pull or push. When an unbalanced ball acts on a force, the ball, the ball will be moved towards the linear motion.
Then, the unbalanced force that is acting in the ball produces torque which causes the ball's rotational motion.