MCQ : Set #9

NOTE : Each set contains 30 questions. Time limit is 45 min.

1. The error in measuring the radius of a sphere is 2%. Then the error in the measurement of its volume is...
   
   
   
   1. 8%
   2. 6%
   3. 2%
   4. 9%
      
   
   
2. A magician is throwing rings into air in such a way that when a ring is at its maximum height he throws another ring. If the time difference between each throw is 1 sec then the height attained by the ring is...
   
   
   
   1. 49 m
   2. 49 cm
   3. 9.8 m
   4. 4.9 m
      
   
   
3. If the mass and force are doubled then the acceleration will...
   
   
   
   1. double
   2. become thrice
   3. become four times
   4. remain same as before
      
   
   
4. A string is tied to the neck of a bottle containing soda water and then whirled in a vertical circle. The bubbles will be found...
   
   
   
   1. near the neck
   2. at the bottom
   3. at the centre
   4. everywhere in the bottle
      
   
   
5. If the absolute temperature of a gas is doubled, then V_rms will become
   
   
   
   1. 2 times
   2. √ 2 times
   3. 1/2 times
   4. 4 times
      
   
   
6. When the temperature of a black body is lowered to half its original value then the amount of heat radiated will be reduced to...
   
   
   
   1. 1/2
   2. 1/4
   3. 1/8
   4. 1/16
      
   
   
7. A shell is fired from a cannon with a velocity V at an angle θ with the horizontal direction. At the highest point in its path it explodes into two pieces of equal mass. One of the pieces retraces its path to the cannon then the speed of the other immediately after the explosion is...
   
   
   
   1. 3Vcosθ
   2. 2Vcosθ
   3. 3/2
   4. (√ 3)Vcosθ/2
      
   
   
8. X-rays have energy of the order of...
   
   
   
   1. 10 eV
   2. 10⁶ eV
   3. infinity
   4. zero
      
   
   
9. In Rutherford model of the atom, the path of an electron will be...
   
   
   
   1. a straight line
   2. parabolic
   3. circular
   4. spiral
      
   
   
10. A double concave lens of glass, placed in a liquid of refractive index 2, will behave as...
    
    
    
    1. diverging lens
    2. concave mirror
    3. converging lens
    4. none of the above
       
    
    
11. Megawattday is the unit of...
    
    
    
    1. power
    2. force
    3. energy
    4. density
       
    
    
12. A particle executes SHM with its frequency f. The frequency with which its kinetic energy oscillates is...
    
    
    
    1. f/2
    2. f
    3. 2f
    4. 4f
       
    
    
13. If the acceleration due to gravity,g, is about 10 m/s² near the surface of the earth, then at the centre of the earth g would have an approximate value of...
    
    
    
    1. zero
    2. 5 m/s²
    3. 10 m/s²
    4. 20 m/s²
       
    
    
14. A tuning fork vibrates at a frequency of f Hz. It is viewed through a stroboscopic disc having four equally spaced slots in it. In order for the vibrating tuning fork to appear stationary, the minimum number of revolutions per second at which the disc should be rotated is...
    
    
    
    1. f/8
    2. f/4
    3. f/2
    4. f
       
    
    
15. Which of the following materials has the greatest relative permittivity?
    
    
    
    1. Air
    2. Glass
    3. Mica
    4. Water
       
    
    
16. The distance between two consecutive antinodes is...
    
    
    
    1. λ
    2. λ/2
    3. λ/3
    4. λ/4
       
    
    
17. For an object below the earth's surface, if the distance of the object from earth's centre is 'd', then the acceleration due to gravity is proportional to...
    
    
    
    1. d
    2. d²
    3. 1/d
    4. 1/d²
       
    
    
18. A type of process that does not need outside energy to reverse is one that occurs at constant...
    
    
    
    1. temperature
    2. pressure
    3. volume
    4. speed
       
    
    
19. Which of the following combinations of length(l) and cross-sectional area(A) will give a certain volume of copper the least resistance?
    
    
    
    1. l and A
    2. 2l and A/2
    3. l/2 and 2A
    4. none
       
    
    
20. Inside a solenoid, the magnetic field...
    
    
    
    1. is zero
    2. is uniform
    3. increases with distance from the axis
    4. decreases with distance from the axis
       
    
    
21. When the voltage are in phase in an a.c. circuit...
    
    
    
    1. impedance is zero
    2. reactance is zero
    3. resistance is zero
    4. phase angle is 90°
       
    
    
22. The distance between two consecutive bright fringes increases as...
    
    
    
    1. the wavelength increases
    2. the frequency increases
    3. the wavelength decreases
    4. the separation of two sources increases
       
    
    
23. Photoelectric effect can be explained on the basis of...
    
    
    
    1. the wave theory of light
    2. the theory of relativity
    3. the theory of black-body radiation
    4. none of the above
       
    
    
24. Acoustics is the branch of physics studying...
    
    
    
    1. light
    2. heat
    3. sound
    4. motion of planets
       
    
    
25. The prefix 'pico' represents...
    
    
    
    1. 10^-9
    2. 10^-12
    3. 10⁹
    4. 10¹²
       
    
    
26. The unit vector in the same direction as(-3i + 4j) is...
    
    
    
    1. (-3/5)i + (4/5)j
    2. -i + j
    3. 3i - 4j
    4. (-1/3)i + (1/4)j
       
    
    
27. An 800-kg car moving at 80 kmph overtakes a 1200-kg car moving at 40 kmph in the same direction. If the two cars stick together,the wreckage has an initial speed of...
    
    
    
    1. 8 kmph
    2. 40 kmph
    3. 56 kmph
    4. 60 kmph
       
    
    
28. For a fixed mass of gas in an isothermal process, the plot of V→(1/p) is...
    
    
    
    1. a straight line
    2. a parabola
    3. a nonparabolic curve
    4. a hyperbolic curve
       
    
    
29. When a vapour condenses into liquid...
    
    
    
    1. it absorbs heat
    2. it volves heat
    3. its temperature rises
    4. its temperature falls
       
    
    
30. For a rectangular glass slab, the entering ray and the emerging ray...
    
    
    
    1. are parallel
    2. form a right angle
    3. form an acute angle
    4. form an obtuse angle