Test Your Knowledge - Free MCQ PRACTICE
by Saksham Chaudhry : Paschim Vihar, New Delhi 110063 T: 1142316457, 9810570740
A fresh set of 20 random questions is generated every time you open this page and every time you refresh it.
For each of the following multiple choice questions, choose the most appropriate answer :

1. When an electron positron pair annihilates, the energy released is about
A. 0.8E-13 J 
B. 1.6E-13 
C. 3.2E-13 J 
D. 4.8E-13 J 

2. An object is thrown upward with a vertical velocity of 128 ft./sec. It will return in
A. 64 secs 
B. 16 ses 
C. 8seconds 
D. 4seconds 

3. A bus is moving on a straight road towards north with a uniform speed of 50 km/hour when it turns through 90. If the speed remains unchanged after turning, the increase in the Velocity of bus in the turning process is
A. 70.7 km/hour along south-west direction 
B. 50 km/hour along west 
C. Zero 
D. 70.7 km/hour along north-west direction 

4. A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved?
A. 14m/s 
B. 8 m/s 
C. 5 m/s 
D. 3m/s 

5. A sphere of mass M and radius R is falling in a viscous fluid. The terminal velocity attained by the falling object will be proportional to
A. R x R 
B. R 
C. 1/R 
D. 1/R/R 

6. A boat is sent across a river with a velocity of 8 km/hr If the resultant velocity of boat is 10 km/hr, then velocity of river is
A. 12.8km/hr 
B. 6 km/hr 
C. 8 km/hr 
D. 10km/hr 

7. Two balloons are filled, one with pure He gas and the other with air. If the pressure and temperature of these balloons are same, then the number of molecules per unit volume is
A. More in the He filled balloon 
B. Ln the ratio of 1:4 
C. 2Same in both balloons 
D. More in air filled balloon 

8. A horizontal platform is rotating with uniform angular velocity around the vertical axis passing through its centre. At some instant of time a viscous fluid of mass m is dropped at the centre and is allowed to spread out and finally fall. The angular velocity during this period
A. decreases initially and increases again 
B. Remams unaltered 
C. Increases contmuously 
D. Decreases continuously 

9. Characteristic X-rays are produced due to
A. Heating of the target 
B. Transfer of energy in collision Ef electrons with atoms in the target 
C. Transfer of momentum in collision of electrons with target atoms 
D. Transition of electrons from higher to lower electronic orbits in an atom 

10. Moving with the same velocity, which of the following has the longest de Broglie wavelength ?
A. Neutron 
B. Proton 
C. Beta - particle 
D. Alpha - particle 

11. Shadows consist of two portions, the umbra and the penumbra. Which statement below applies ONLY to the umbra?
A. Lt receives no light from any part of the source 
B. It is circular in shape 
C. Lt is a partial shadow 
D. Lt receives light from part of the source 

12. Nuclear fusion is possible
A. Only between nuclei which are stable against beta-decay 
B. Between both light and heavy nuclei 
C. Only between light nudei 
D. Only between heavy nuclei 

13. The horizontal rangeis four times the maximum height attained by a projectile. The angel of projectile is
A. 30 
B. 45 
C. 90 
D. 60 

14. A boat at anchor is rocked by waves whose crests are 100 m apart and velocity is 25 m/sec. The boat bounces up once in every
A. 2500 s 
B. 75 s 
C. 4 s 
D. 0.25 s 

15. In an electrolyte 3.2E18 bivalent positive ions drift to the right per second while 3.6E18 monovalent negative ions drift to the left per second. Then the current is
A. 1.6 amp to the left 
B. 1.6 amp to the right 
C. 0.45 to the right 
D. 0.45 amp to the left 

16. A battery is connected across a resistance wire of uniform cross-section. If another resistance wire is connected in parallel. then the intensity of electric field in the first wire will
A. Be halved 
B. Be doubled 
C. Become zero 
D. Remain unchanged 

17. When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is
A. Of shorter wavelength 
B. Polarized 
C. Of high intensity 
D. Of longer wavelength 

18. A telescope has an objective lens of focal length 200 cm and an eye piece with focal length 2 cm. If this telescope is used to see a 50 metre tall building at a distance of 2 km. what is the height of the image of the building formed by the objective lens ?
A. 2cm 
B. 5cm 
C. 10cm 
D. 1 cm 

19. When light of wavelength 300 nm nanometre falls on a photoelec' tric emitter, photoelectrons are just liberated. For another emitter however, light of 600 nm wave length is sufficient for creating photoemission. What is the ram of the work function of the tWI emitters?
A. 1 : 2 
B. 2 : 1 
C. 4 : 1 
D. 1 : 4 

20. The maximum distance upto which TV transmission from a TV tower of height h can be received is proportional to
A. H1/2 
B. H 
C. H3/2 
D. H2 

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