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. A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is C then the resultant capacitance is
A. n-1C
B. n+1C
C. C
D. nC
2. The maximum range of a gun of horizontal terrain is 16 km. If g= 10 ms then muzzle velocity of a shell must be ?
A. 160 m/s
B. 200?2 m/s
C. 400 m/s
D. 800 m/s
3. lf the density of a given body is 10 gm/cms, what is its specific gravity ?
A. 0.01
B. 1.0
C. 1.0
D. 10.0
4. 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. zero
C. 50 km/hour along west
D. 70.7 km/hour along north-west direction
5. 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
6. The angle between two vectors of magnitude 12 and 18 units when their resultant is 24 units,is ?
A. 63°51'
B. 82°31’
C. 75°52'
D. 89°16’
7. If a planet of given density were: made larger keeping its density unchanged its force of attraction for an object on its surface would increase because of increased mass of the planet but would decrease because of larger separation between the centre of the planet and its surface. Which effect would dominate?
A. Increase in mass
B. Increase in radius
C. Both affect the attraction equally
D. None of the above
8. We wish to see inside an atom, Assuming the atom to have a diameter of 100 pm, this means that one must be able to resolve a width of say 10 pm. If an electron microscope is used, the minimum electron energy required is about
A. 1.5 keV
B. 15 keV
C. 150 keV
D. 1.5 MeV
9. In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer having electron density 1011 per m-3?
A. 2 MHz
B. 10 MHz
C. 12 MHz
D. 18 MHz
10. An electron is travelling along the x-directlon . It encounters a magnetic field in the y-direction . Its subsequent motion will be
A. Straight line along the x-direction
B. A circle in the xz-plane
C. A circle in the yz-plane
D. A circle in the xy-plane
11. An astronaut is looking down on earth's surface from a space shuttle at an altitude of 400 km. Assuming that the astronaut's pupil diameter is 5 mm and the wavelength of visible light is 500 nm. The astronaut will be able to resolve linear objects of the size of about
A. 0.5 m
B. 5 m
C. 50 m
D. 500 m
12. If the universal gas constant is R and Boltzmann constant is K, then number of molecules in a mol of hydrogen will be
A. K/R
B. R/2K
C. R/K
D. 2R/K
13. Which of the statements below is courect ?
A. The angle of bank for a road is obtained from a consideration of the centripetal force required
B. There is no tendency for the vehicle to skid if a road is banked for the speed at which the vehicle is moving
C. C. The resultant force action on the vehicle will be that which maintains it in the circular path
D. All of the above statements are correct
14. When you make lce cubes, the entropy of water
A. Does not change
B. Increases
C. Decreases
D. May either increase or decrease depending on the process used
15. A solenoid has 2000 turns wound over a length of 0.30 m. The area of its cross-section is 1.2 x 10- 3 m2. Around its central section a coil of 300 turns is wound. If an initial current of 2A in the solenoid is reversed in 0.25 see, the emf induced in the coil is
A. 48 volt
B. 8 4.8 volt
C. 4.8 x 10-1 volt
D. 4.8 x 10- 2 volt
16. A monochromatic beam of light is used for the formation of fringes on the screen by illuminating the two slits in the Young’s double slit interference experiment. When a thin film of mica is interposed in the path of one of the interfering beams then
A. The fringe width increases
B. The fringe width decreases
C. The fringe width remains the same but the pattem shifts
D. The fringe pattem disappears
17. When a monochromatic point source of light is at a distance of 0.2 m from a photocell, the cutoff voltage and the saturation current are respectively Vo = 0.6 volt and is = 18.0 mA. If the same source is placed 0.6 m away from the photocell, then
A. Stopping potential Vo = 0.2 volt and saturation current is = 18.0 mA
B. Stopping potential Vo = 0.6 volt and saturation current is = 18.0 mA
C. Stopping potential Vo = 0.6 volt and saturation currenl is = 2.0 mA
D. Stopping potential Vo = 0,2 volt and saturation current is=2.0mA
18. By sucking through a straw. a student can reduce the pressure in his lungs to 750 mm of Hg density 13.6 gm/cc. Using the straw. he can drink water from a glass upto a maximum depth of
A. 10 cm
B. 75 cm
C. 13.6 cm
D. 1.36 cm
19. The specific charge of an electron is
A. 5.7E7 Coulomb/kg
B. 1.76E11 Coulomb/kg
C. 1.6E-19 Coulomb/gm
D. 1.6E-19 Coulomb
20. The voltage oi clouds is 4E6 volt with respect to ground. In a lightening strike lasting 100 m sec. charge of 4 conlombs is delivered to the ground. The power oi lightening strike is
A. 160 MW
B. 80 MW
C. 2O MW
D. 500 KW
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