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10.

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13.

The angle of contact depends on
i. The nature of the liquid.
ii. The solid with which it is in contact.
iii. The purity of solid and liquid.
iv. Nature of the vapour.
A) i, ii and iii B) ii, iii and iv
C) i, ii, iii and iv D) i, iii and iv

. Which of the following is the relation between numerical aperture and acceptance angle

in the case of optical fibre communication ? Symbols have the usual meaning

A) Sin®g = no(n? — n3) 42
8) 81100 = ng (11-15) /?
C) Sindy = 71८17 -72)2
ഉ) ng! Sin@y = )02 - 42

In Fraunhoffer single slit diffraction pattern, a screen is placed 1m away from the
lens to obtain the pattern. Which is the wavelength of light if the slit width is 0.2 mm
and the first minima lie 2.5 mm on either side of the central maximum ?

A) 4500A B) 5500 A C) 4000A D) 5000A

A Carnot’s engine working between 127°C and 27°C absorbs 60 cals of heat. How
much heat is rejected ?

A) 65 cals 8) 45 cals C) 35 cals D) 25 cals

What is the ratio of extension produced in the wires of the same material, subjected
to a force in the ratio of 4: 1 and their lengths and radius are in the ratio of 1: 16
and 1 : 4 respectively ?

A) 2:1 B) 1:2 Cc) 1:4 D) 1:1

The correct order of bond angles in NH3, PH3, AsH3 and 50113 is
A) PH3 > NH > AsHg > SbH3
8) NHg > PH3 > AsH3 > SbH3
©) SbH, > AsH3 > PH3 > NH3
D) AsH, > SbHg > PH; > NH,