If an interference pattern have maximum and minimum intensities in 36 : 1 ratio then what will be the ratio of amplitudes
|
(a) 5 : 7 |
(b) 7 : 4 |
(c) 4 : 7 |
(d) 7 : 5 |
(d) 7 : 5
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Two thin lenses of focal lengths 20 cm and 25 cm are placed in contact convex. The effective power of the combination is
|
(a) 45 dioptres |
(b) 9 dioptres |
(c) 1/9 dioptre |
(d) 6 dioptres |
An electron has mass 9 
and charge 1.6 
is moving with a velocity of 
, enters a region where magnetic field exists. If it describes a circle of radius 0.10 m, the intensity of magnetic field must be
|
(a) 1.8 |
(b) 5.6 |
(c) 14.4 |
(d) 1.3 |
Which of the following statement is correct
|
(a) Both Peltier and Joule effects are reversible |
|
(b) Both Peltier and Joule effects are irreversible |
|
(c) Joule effect is reversible, whereas Peltier effect is irreversible |
|
(d) Joule effect is irreversible, whereas Peltier effect is reversible |
Three capacitors of 2μF, 3μF and 6μF are joined in series and the combination is charged by means of a 24 volt battery. The potential difference between the plates of the 6 μF capacitor is
|
(a) 4 volt |
(b) 6 volt |
(c) 8 volt |
(d) 10 volt |
The potential at a distance R/2 from the centre of a conducting sphere of radius R will be
|
(a) 0 |
(b) |
(c) |
(d) |
| C-1 (waves) | C-II (Production) |
| (1) Infra-red | P. Rapid vibration of electrons in aerials |
| (2) Radio | Q. Electrons in atoms emit light when they move from higher to lower energy level. |
| (3) Light | R. Klystron valve |
| (4) Microwave | S. Vibration of atoms and molecules |
In a Ag voltameter 2.68 gm of silver is deposited in 10 min. The heat developed in 20Ω resistor during the same period will be
|
(a) 192 kJ |
(b) 192 J |
(c) 200 J |
(d) 132 kJ |
In electrolysis, if the duration of the passage of current is doubled, the mass liberated i
|
(a) Doubled |
(b) Halved |
(c) Increased four times |
(d) Remains the same |
