The cylindrical tube of a spray pump has a cross-section of \(8\) cm2 one end of which has \(40\) fine holes each of area \(10^{-8}\) m2. If the liquid flows inside the tube with a speed of \(0.15\) m min-1 the speed with which the liquid is ejected through the holes is:
1. \(50\) m/s
2. \(5\) m/s
3. \(0.05\) m/s
4. \(0.5\) m/s
Subtopic:  Equation of Continuity |
 59%
Please attempt this question first.
Hints

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.
Subtopic:  Einstein's Photoelectric Equation |
Please attempt this question first.
Hints

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. \(\frac{n d}{d+\sqrt{2} n}\)

 

Subtopic:  Refraction at Plane Surface |
 58%
Please attempt this question first.
Hints

advertisementadvertisement

A shell of mass \(20\) kg at rest explodes into two fragments whose masses are in the ratio \(2:3.\) The smaller fragment moves with a velocity of \(6\) m/s. The kinetic energy of the larger fragment is:
1. \(96\) J
2. \(216\) J
3. \(144\) J
4. \(360\) J

Subtopic:  Collisions |
 57%
Please attempt this question first.
Hints

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

Subtopic:  Self - Inductance |
Please attempt this question first.
Hints

In Young's double slit experiment with sodium vapour lamp of wavelength \(589\) nm and the slits \(0.589\) mm apart, the half angular width of the central maximum is:
1. \(sin^{-1} (0.01)\)
2. \(sin^{-1} (0.0001)\)
3. \(sin^{-1} (0.001)\)
4. \(sin^{-1} (0.1)\)

Subtopic:  Young's Double Slit Experiment |
 61%
Please attempt this question first.
Hints

advertisementadvertisement

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. \(\frac{KC}{4}\)

 

Subtopic:  Dielectrics in Capacitors |
 54%
Please attempt this question first.
Hints

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

1. can keep the body in equilibrium if \(2\) N and \(3\) N act at right angle.
2. can keep the body in equilibrium if \(1\) N and \(2\) N act at right angle.
3. cannot keep the body in equilibrium.
4. can keep the body in equilibrium in \(1\) N and \(3\) N acts at an acute angle.

Subtopic:  Resultant of Vectors |
 55%
Please attempt this question first.
Hints

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

Subtopic:  Work Done by Variable Force |
Please attempt this question first.
Hints

advertisementadvertisement

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:
       
 

1. changing continuously with time
2. greater at M than at N
3. greater at N than at M
4. same at M and N
Subtopic:  Equation of Continuity |
Please attempt this question first.
Hints