In a two slit experiment with monochromatic light fringes are obtained on a screen placed at some distance from the sits. If the screen is moved by 5 
towards the slits, the change in fringe width is 3 
. If separation between the slits is 
, the wavelength of light used is
|
(a) 6000 Å |
(b) 5000 Å |
(c) 3000 Å |
(d) 4500 Å |
(a) 6000 Å
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State which of the following is correct
|
(a) Joule = coulomb × volt |
(b) Joule = coulomb/volt |
|
(c) Joule = volt × ampere |
(d) Joule = volt/ampere |
The magnifying power of a microscope with an objective of 5 mm focal length is 400. The length of its tube is 20 cm. Then the focal length of the eye-piece is
|
(a) 200 cm |
(b) 160 cm |
(c) 2.5 cm |
(d) 0.1 cm |
ABC is a right angled triangle in which AB = 3 cm and BC = 4 cm. And Ð ABC = p/2. The three charges +15, +12 and -20 e.s.u. are placed respectively on A, B and C. The force acting on B is
|
(a) 125 dynes |
(b) 35 dynes |
(c) 25 dynes |
(d) Zero |
Assertion : Neutral temperature of a thermocouple does not depend upon temperature of cold junction.
Reason : Its value is constant for the given metals of the couple.
|
(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. |
|
(c) If assertion is true but reason is false. |
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(d) If the assertion and reason both are false. |
A capacitor of capacity C is connected with a battery of potential V in parallel. The distance between its plates is reduced to half at once, assuming that the charge remains the same. Then to charge the capacitance upto the potential V again, the energy given by the battery will be
|
(a) |
(b) |
(c) |
(d) |
Different voltages are applied across a P-N junction and the currents are measured for each value. Which of the following graphs is obtained between voltage and current
(a)
|
(b)
|
(c)
|
(d)
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Two capacitors 
and 
in series, are connected in parallel to a third capacitor
. This arrangement is then connected to a battery of e.m.f. = 2V, as shown in the figure. How much energy is lost by the battery in charging the capacitors
|
(a) 22 |
(b) 11 |
(c) |
(d) |
