A beam with wavelength 
falls on a stack of partially reflecting planes with separation d. The angle q that the beam should make with the planes so that the beams reflected from successive planes may interfere constructively is (where n = 1, 2, ……)
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(a) |
(b) |
(c) |
(d) |
(c) 
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Assertion : Television signals are received through sky-wave propagation.
Reason : The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency.
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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. |
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(d) If the assertion and reason both are false. |
Total flux produced by a source of 1 cd is
|
(a) |
(b) 8 |
(c) 4 |
(d) |
In a fission process, nucleus A divides into two nuclei B and C, their binding energies being 
and 
respectively. Then
|
(a) |
(b) |
(c) |
(d) |
A battery of 6 volts is connected to the terminals of a three metre long wire of uniform thickness and resistance of the order of 100 Ω. The difference of potential between two points separated by 50 cm on the wire will be
|
(a) 1 V |
(b) 1.5 V |
(c) 2 V |
(d) 3 V |
A 10 pF capacitor is connected to a 50 V battery. How much electrostatic energy is stored in the capacitor
|
(a) 1.25 |
(b) 2.5 |
(c) 3.5 |
(d) 4.5 |
A toroid has number of turns per unit length n, current i, then the magnetic field is
|
(a) |
(b) |
(c) |
(d) None of these |
