Which one of the following graphs represents the variation of maximum kinetic energy \((E_k)\) of the emitted electrons with frequency \(\nu\) in photoelectric effect correctly?  

1.		2.
3.		4.

A vessel of height \(2~d\) is half filled with a liquid of refractive index \(\sqrt2\) and the other half with a liquid of refractive index \(n\) (the given liquids are immiscible). Then, the apparent depth of the inner surface of the bottom of the vessel (neglecting the thickness of the bottom of the vessel) will be:
1. \(\frac{n}{d(n+\sqrt{2})}\)
2. \(\frac{d(n+\sqrt{2})}{n \sqrt{2}}\)
3. \(\frac{\sqrt{2} n}{d(n+\sqrt{2})}\)
4. \(\frac{n d}{d+\sqrt{2} n}\)

An electric bulb has a rated power of \(50\) W at \(100\) V. If it is used on an AC source \(200\) V, \(50\) Hz, a choke has to be used in series with it. This choke should have an inductance of:
1. \(0.1\) mH
2. \(1\) mH
3. \(0.1\) H
4. \(1.1\) H

A parallel plate capacitor with air as the dielectric has capacitance \(C.\) A slab of dielectric constant \(K\) having the same thickness as the separation between the plates is introduced so as to fill one-fourth of the capacitor as shown in the figure. The new capacitance will be: 
        
1. \((K+3)\frac C4\)
2. \((K+2)\frac C4\)
3. \((K+1)\frac C4\)
4. \(\frac{KC}{4}\)

Three concurrent co-planar forces \(1\) N, \(2\) N and \(3\) N acting along different directions on a body.
Choose the correct statement:

The work done by force acting on a body is as shown in the graph. The total work done in covering an initial distance of \(20\) m is: 
        
1. \(212.5\) J
2. \(200\) J
3. \(400\) J
4. \(175\) J

Horizontal tube of non-uniform cross-section has radii of \(0.1\) m and \(0.05\) m respectively at M and N. For a streamlined flow of the liquid, the rate of liquid flow is: