A nuclear power plant supplying electrical power to the village uses a radioactive material of half life T years as the fuel. The amount of fuel at the beginning such that the total power requirement of the village is 12.5 % of the electrical power available from the plant at that time. If the plant is able to meet the total power needs of the village for a maximum period of n T years, then the value of n is

1) 1
2) 3
3) 5
4) 7

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio

1) 25 : 1

2) 5 : 1

3) 9 : 4

4) 25 : 16

A nucleus of mass M + ?m is at rest and decays into two daughter nuclei of equal mass (M/2) each. Speed of light is c. 
The speed of daughter nuclei is

When a string is under a tension of 100 N, a pulse travels down it at a speed of 100 m/s. If you double the tension in the string to 200 N, the pulse would travel at about:

 The maximum height reached by a projectile is 4 metres. The horizontal range is 12 metres. Velocity of project in ms^–1 is (g – acceleration due to gravity)

A block of mass 1 kg slides down on a rough inclined plane of inclination 60^o starting from its top. If the coefficient of kinetic friction is 0.5 and length of the plane is 1 m, then work done against friction is  (Take g = 9.8 m/s²)

1) 9.82 J

2) 4.94 J

3) 2.45J

4) 1.96 J

The energy [E ] , angular momentum ( L)  and universal gravitational constant (G)  are chosen as fundamental quantities. The dimensions of universal gravitational constant in the dimensional formula of planks constant (h)  is.  
1) 0
2) -1
3)  5 / 3
4) 1 

An n-p-n transistor of current gain 80 in common emitter mode gives emitter current equal to 8.1 mA. The base current is

1) 0.1 $$\mu$$A
2) 0.1 mA
3) 0.01 mA
4) 0.01 $$\mu$$A

A lens of focal length 20cm is used to produce a 10 times magnified image of a slim slide on a screen.. How far must the slide be placed from the lens

1) 220 cm
2) 180 cm
3) 40.5 cm
4) 200 cm

What percentage of original radioactive atoms is left after five half lives?

1) 5 %
2) 3 %
3) 10 %
4) 20 %