In Young’s double-slit experiment, an interference pattern is obtained on a screen by a light of wavelength 6000 Å, coming from the coherent sources S1 and S2. At certain point P on the screen third dark fringe is formed. Then the path difference S1P – S2P in microns is
|
(a) 0.75 |
(b) 1.5 |
(c) 3.0 |
(d) 4.5 |
(b) 1.5
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A semiconductor dopped with a donor impurity is
|
(a) P-type |
(b) N-type |
(c) NPN type |
(d) PNP type |
The diode shown in the circuit is a silicon diode. The potential difference between the points A and B will be
|
(a) 6 V |
(b) 0.6 V |
(c) 0.7 V |
(d) 0 V |
Resistance of a voltameter is 2Ω, it is connected in series to a battery of 10 V through a resistance of 3Ω. In a certain time mass deposited on cathode is 1 gm. Now the voltameter and the 3Ω resistance are connected in parallel with the battery. Increase in the deposited mass on cathode in the same time will be
|
(a) 0 |
(b) 1.5 gm |
(c) 2.5 gm |
(d) 2 gm |
A double convex thin lens made of glass of refractive index 1.6 has radii of curvature 15 cm each. The focal length of this lens when immersed in a liquid of refractive index 1.63 is
|
(a) – 407 cm |
(b) 250 cm |
(c) 125 cm |
(d) 25 cm |
Three wires of copper, iron and nickel are joined to form three junctions as shown in Fig. When the temperature of junction 1 is kept 50℃ with the other two junctions at 0℃, the sensitive galvanometer gives a deflection of 14 divisions. When the temperature of junction 3 is kept 50℃, with the other two junctions at 0℃, the galvanometer gives a deflection of 11 divisions. Then the deflection given by the galvanometer, when temperature of the junction 2 is kept at 50℃, with the other two junctions at 0℃, will be
|
(a) 3 div |
(b) 11 div |
(c) 14 div |
(d) 25 div |
An electric line of force in the xy plane is given by equation 
. A particle with unit positive charge, initially at rest at the point x = 1, y = 0 in the xy plane
|
(a) Not move at all |
|
(b) Will move along straight line |
|
(c) Will move along the circular line of force |
|
(d) Information is insufficient to draw any conclusion |