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प्रश्न
When Puja, a student of 10th class, watched her mother washing clothes in the open, she observed coloured soap bubbles and was curious to know why the soap bubbles appear coloured. In the evening when her father, an engineer by profession, came home, she asked him this question. Her father explained to her the basic phenomenon of physics due to which the soap bubbles appear coloured.
(a) What according to you are the values displayed by Puja and her father?
(b) State the phenomenon of light involved in the formation of coloured soap bubbles.
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उत्तर
(a) Puja displayed the values of great observation and curiosity to learn. Her father displayed the values of being a good father by considering her doubts serious and explaining them well to her.
(b) The phenomenon of light involved in the formation of coloured soap bubbles is interference of light on a thin film.
संबंधित प्रश्न
The magnetic flux through a loop varies according to the relation Φ = 8t2 + 6t + C, where ‘C’ is constant, 'Φ' is in milliweber and 't' is in second. What is the magnitude of induced e.m.f. in the loop at t = 2 seconds.
An emf of 2V is induced in a coil when the current in it is changed from 0A to 10A in 0·40 sec. Find the coefficient of self-inductance of the coil.
What is an electromagnet? Describe the construction and working of an electromagnet with the help of a labelled diagram.
Write some of the important uses of electromagnets.
Describe one experiment to demonstrate the phenomenon of electromagnetic induction.
The following diagram shows a fixed coil of several turns connected to a center zero galvanometer G and a magnet NS which can move in the direction shown in the diagram.
- Describe the observation in the galvanometer if
- The magnet is moved rapidly,
- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?
You have been provided with a solenoid AB.
(i) What is the polarity at end A?
(ii) Give one advantage of an electromagnet over a permanent magnet.
Write Fleming’s right hand thumb rule with the help of diagram.
The instrument that use to defect electric current in the circuit is known as ____________.
One solenoid is centered inside another. The outer one has a length of 50.0 cm and contains 6750 coils, while the coaxial inner solenoid is 3.0 cm long and π cm2 in area and contains 150 coils. The current in the outer solenoid is changing at 3000 A/s. The emf induced in the inner solenoid is ______ V.
(Round off to two decimal places.)
