W.B Joint Entrance 2010 Physics and Chemistry Paper(English Version)

 

1. Experimental investigations show that the intensity of solar radiation is maximum for a wavelength 480 nm in the visible region. Estimate the surface temperature of sun. Given Wein’s constant b = 2.88 × 10–3 mK.

(A) 4000 K   (B) 6000 K    (C) 8000 K    (D) 106 K

 

 

2. The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K, the root mean square speed of gas molecules is v, then at 480 K it will be

(A) 4v    (B) 2v    (C) 2v    (D) 4v

 

3. Two mirrors at an angle θº produce 5 images of a point. The number of images produced when θ is decreased to θº – 30º is

(A) 9   (B) 10    (C) 11     (D) 12

 

4. The radius of the light circle observed by a fish at a depth of 12 meter is (refractive index of water = 4/3)

 

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