In human eye, the image of an object is formed at______
Answer: In the human eye, the image of an object is formed at the retina. Human eye The eye is an... View Article
Latest Posts
What does the solar system consist of?
Answer: The sun and the celestial bodies that revolve around it form the solar system. These include the sun itself,... View Article
The most comfortable distance at which one can read with a normal eye is about ________ cm.
The most comfortable distance at which one can read with a normal eye is about 25 cm.
Atul came to know from his father that pole star is the only star in the sky that does not move as the night passes. But his father did not tell him the reason. Can you help him?
Stars appear moving because of earth’s rotation. But pole star is located in direction of earth’s axis. So there is... View Article
A N-typesemiconductor is [AFMC 1988; RPMT 1999]
N-type semiconductors are neutral because neutral atoms are added during doping.
What is the principle behind ocean thermal energy?Statement1: The warm water at surface is used to boil ammonia , which vaporizes and then used to rotate turbine. Statement 2: the ammonia is vaporized as only then it gains sufficient kinetic energy for power generation.
The water at the surface of the sea or ocean is heated by the Sun while the water in deeper... View Article
Light year is the unit of distance. It is the distance travelled by light in one year. If the speed of light is equal to 3×108 m/s , how many kilo-meters will make up 1 light year?
1 Light year = speed x time = 3 x 108 m/s x 365... View Article
Alternating current can not be measured by dc ammeter because
In dc ammeter, a coil is free to rotate in the magnetic field of a fixed magnet. If an alternating current is... View Article
Tarun got to know from his elder brother that sun is the nearest star and is approximately 150 million kilometers away from the earth. He wanted to know which is the next nearest star and what is its distance from the earth. His tutor told him that the nearest star is proxima centauri and is at a distance of 4.3 light years from the earth. Tarun does not know what a light year is. Can you tell him?
One light year is the distance travelled by the light in one year.
The reading of ammeter in the circuit shown will be
Given XL = XC = 5Ω this is the condition of resonance. Since VL = VC net voltage across L and... View Article
Sun is also a star but it looks larger than other stars. Why?
Sun is also a star but it looks larger than other stars because other stars are millions of times farther... View Article
A bulb and a capacitor are connected in series to a source of alternating current. If its frequency is increased, while keeping the voltage of the source constant, then
When a bulb and a capacitor are connected in series to an ac source, then on increasing the frequency the... View Article
Why can’t we easily see stars and planets in the sky when we are in a city but can easily see them elsewhere?
Due to pollution, there are many particles in the air, which absorb the light coming from the distant stars and... View Article
Rahul had gone to his village in summer vacation. After dinner, he went on the roof with his cousin. He saw countless bright objects in the sky. His mother had told him that the bright objects that twinkle in the sky are called stars. But he saw a few objects that were bright but they were not twinkling. What were they?
The bright objects which are not shining were planets.
Which of these options look similar to the constellation Cassiopeia?
Cassiopeia looks like a distorted letter W or M
If A and B are identical bulbs which bulbs glows brighter
(XC) >> (XL) As the impedance is more in capacitor, bulb B will be glows less brighter compared to Bulb... View Article
Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.
The air gets trapped between two layers of warm clothes. Air acts as insulator of heat. This layer prevents our... View Article
Following figure shows an ac generator connected to a “block box” through a pair of terminals. The box contains possible R, L, C or their combination, whose elements and arrangements are not known to us. Measurements outside the box reveals that e = 75 sin (sin omega t) volt, i = 1.5 sin ( omega t + 45o) amp then, the wrong statement is
Since voltage is lagging behind the current, so there must be no inductor in the box.
The vector diagram of current and voltage for a circuit is as shown. The components of the circuit will be 635056321029926369_6005818.PNG
From phasor diagram it is clear that current is lagging with respect to Erms. This may be happen in LCR... View Article
Sam’s father and mother are astronauts. Last month they returned from a tour to moon. Sam’s father told him that they had air filled helmet and it also had microphone, which they used for talking to each other. But his mother was not able to listen to him when they opened their helmets. (Assume they were wearing oxygen masks when they opened their helmets). What is the reason?
There is no atmosphere on the moon. Sound needs a medium to travel and since there is no air, sound... View Article
