If a ray of light is incident at an angle of 60 degrees to the normal, then the angle formed by the reflected ray with the normal is equal to
According to the first law of reflection, the angle of incidence is equal to the angle of reflection
Latest Posts
A 1 cm high object is placed at a distance of 32 cm from a concave mirror. The image is real, inverted and 1.5 cm in size. Calculate the focal length of the mirror and the position of the image.
Given that Distance of the object placed from a concave mirror u = -32 cm ho = 1cm As the... View Article
If you took a snap of a guy who looks like this using a pinhole camera: How will the image on the screen look like?
b. A pinhole camera forms an inverted image, as you just learnt.
Friction that exists between two surfaces in contact, when there is no relative motion between them is called as?
The friction that exists between two surfaces in contact, when there is no relative motion between them is called static... View Article
The force which needs to be overcome at the instant an object starts moving from rest is
Static friction arises from the interlocking of irregularities of two surfaces and this prevents any relative motion up to a... View Article
You will find it hard to drag a mat if?
When a person is sitting on the matthe total mass increases. The force of friction increases as the two surfaces... View Article
A cube is pushed such that it slides on a horizontal surface. The friction can be increased by?
When mass of the block is decreased or the surface is polished, the friction is decreased. When another block of... View Article
Calculate the pressure developed by a force of 50N acting on an area of 10m2.
Pressure is defined as the force per unit area, so here pressure developed would be simple force divided by the... View Article
A circular disc is rotating with constant angular velocity ω about an axis that passes through the centre. A particle ‘P’ is kept at a distance of 2m from the centre and another particle ‘Q’ at a distance of 3m from the centre. Which of these will have higher centripetal acceleration?
If a particle goes in a circle with constant ω then it has a centripetal acceleration given by ω2R. since... View Article
A fly was sitting on a block. A man draws a circle of area 2cm2, thus enclosing the fly. He then applies a force of 20N and kills it with a flat stick. Calculate the pressure on that area.
The area on which the pressure is calculated is 2 cm2, and the force applied by the stick is 20N... View Article
If 10^20 electrons flow from the black body to the red body through the copper wire in 8 seconds, then find the current flowing between them.
We know that, q = ne Also, I = q/t Hence, I = ne/t = (1020 x 1.6 x 10-19) /... View Article
If a toy fan is connected across a battery for 2 minutes and we know that a charge transfer of 120 C takes place then find out the current in the circuit for that period of time.
Rate of flow of charge is called current. Hence, I=q/t =120 / (2 x 60) = 1 A
A body of dimensions (lxbxh) 2m x 3m x 4m is acted upon by a force of 50N on the top surface. Calculate the pressure due the force on that surface.
This body could be taken as a cuboid of dimensions 2m x 3m x 4m.So, 2m is the length, 3m... View Article
There are 2 school bags A & B. Bag A is provided with a broader strap while bag B is provided with a thinner strap. For the same load, a school boy likes bag A as he is comfortable with it, but with bag B, he develops a pain in his shoulders. Why?
Since, the pressure is the force per unit area therefore, in bag A as the straps are broader, the pressure... View Article
A mosquito is making sound with its wings at an average rate of 500 vibrations per 10 seconds. The frequency of vibrations is
The number of oscillations per second= 500/10 = 50 Hz.
A chef while cooking cuts his hand with a sharp edged knife, but to his surprise his hand did not cut with a spoon even on the application of a greater force. Why it did cut from a knife for a smaller force.
Since the edge of the knife is very sharp, therefore the pressure developed is much larger for the same force... View Article
What is Gravitational force?
The universal force of attraction acting between all matter is the gravitational force. It is by far the weakest known... View Article
What part of human body is responsible for the voice production?
In humans, the sound of speech is produced by the Larynx or Vocal cord.
A little boy was playing tug of war with his elder brother; he tried everything but was unsuccessful in pulling the rope towards himself. Eventually, little boy lost the game because:- Statement1: Elder brother was capable of applying a greater force than his younger brother and hence the net force was in a direction to make him win. Statement2: An object moves in the direction of net force acting on it.
His elder brother was able to apply a larger force and hence the net force was in a direction which... View Article
A cannon ball (mass = 2 kg) is fired at a target of 500 meters away. The 400 kg cannon recoils by 50 cm. Assuming cannon ball moves with constant velocity, when will it hit the target? [Resistance offered by ground to cannon is 100 N]
Force by ground on the cannon = 100N. Work done by ground on the cannon = 100 x(0.5) = 50J.... View Article
