- A$\frac{1}{100}\text{second}$
- B100 second
- C50 second
- DNone of these
Explanation:
In India, the frequency of AC voltage is 50 Hz.
It means 50 waves will be produced in 1 s.
In one wave, the direction is changed 2 times.
Thus, in 50 waves, the direction will be altered 50 × 2 = 100 times.
i.e. the direction is changed 100 times in 1 s.
Thus the direction is changed in every $\frac{1}{100}\text{second}$
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In the process of electrolysis, the current is carried out inside the electrolyte by
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(a) Electrons |
(b) Atoms |
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(c) Positive and negative ions |
(d) All the above |
The ratio of the speed of the electron in the first Bohr orbit of hydrogen and the speed of light is equal to (where e, h and c have their usual meanings)
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(a) 2πhc/ |
(b) |
(c) |
(d) 2π |
The half-life of radon is 3.8 days. Three forth of a radon sample decay in
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(a) 5.02 days |
(b) 15.2 days |
(c) 7.6 days |
(d) 11.4 days |
Assertion : Two bulbs of same wattage, one having a carbon filament and the other having a metallic filament are connected in series. Metallic bulbs will glow more brightly than carbon filament bulb.
Reason : Carbon is a semiconductor.
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(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
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(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
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(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
Two coherent sources S1 and S2 are separated by a distance four times the wavelength l of the source. The sources lie along y axis whereas a detector moves along + x axis. Leaving the origin and far off points the number of points where maxima are observed is
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(a) 2 |
(b) 3 |
(c) 4 |
(d) 5 |
You are given four sources of light each one providing a light of a single colour – red, blue, green and yellow. Suppose the angle of refraction for a beam of yellow light corresponding to a particular angle of incidence at the interface of two media is 90º. Which of the following statements is correct if the source of yellow light is replaced with that of other lights without changing the angle of incidence?