MCQ : Set #5

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

1. T is the period of oscillation for a spring-mass system on earth. Its period on moon is...
   
   
   
   1. T
   2. 6T
   3. T/6
   4. √ 6T
      
   
   
2. In a stretched string, the speed of waves depends on...
   
   
   
   1. the tension in the string
   2. the amplitude
   3. the wavelength
   4. the acceleration due to gravity
      
   
   
3. For a plane curved path with radius of curvature R without slope the maximum safe velocity of the vehicle(v) is proportional to...
   
   
   
   1. R
   2. R²
   3. √R
   4. 1/R
      
   
   
4. Two projectiles A and B are projected with same initial velocity. The direction of A makes an angle α_A = π/4 with the horizontal.The direction of B makes an angle α_B with the horizontal. The range of A will be double that of B for α_B equal to...
   
   
   
   1. π/8
   2. π/2
   3. π/3
   4. π/12
      
   
   
5. A frictionless heat engine can be 100% efficient only its exhaust temperature is...
   
   
   
   1. equal to its input temperature
   2. 0°C
   3. less than the input temperature
   4. 0 K
      
   
   
6. The resistance of conductor is R. The resistance of another conductor of identical material and equal length with twice the diameter is...
   
   
   
   1. R/4
   2. R/2
   3. 2R
   4. 4R
      
   
   
7. The magnitude of the magnetic field B at a point on the axis near the centre of the infinitely long solenoid having n turns per unit length and carrying a current I is given by...
   
   
   
   1. μ₀nI
   2. μ₀I/n
   3. (μ₀nI)/4π
   4. μ₀I/4πn
      
   
   
8. The impedance of a circuit does not depend on...
   
   
   
   1. f
   2. I
   3. C
   4. R
      
   
   
9. Shadows are never completely dark because of...
   
   
   
   1. interference
   2. diffraction
   3. polarization
   4. reflection
      
   
   
10. Threshold frequency is the characteristic of...
    
    
    
    1. the incident radiation
    2. the emitted electrons
    3. the metal
    4. both radiation and the metal
       
    
    
11. In the hydrogen spectrum,the seriesv obtained in the visible region is...
    
    
    
    1. Balmer series
    2. Lyman series
    3. Paschen series
    4. Brackett series
       
    
    
12. Out of four different atoms:₄₆A²², ₄₈B²², ₄₆C²³, ₄₄D²⁰, the pair of isotones is...
    
    
    
    1. A and B
    2. B and C
    3. A and C
    4. A and D
       
    
    
13. In a common-base circuit, the current gain is...
    
    
    
    1. 0
    2. 1
    3. less than 1
    4. greater than 1
       
    
    
14. The magnitude of the resultant of two forces is a minimum when the angle between them is...
    
    
    
    1. 0°
    2. 45°
    3. 90°
    4. 180°
       
    
    
15. Work done on the particle in uniform circular motion is...
    
    
    
    1. always positive
    2. always negative
    3. always zero
    4. directly proportional to the force
       
    
    
16. An 800-kg car moving at 80 kmph collides head-on with a 1200-kg car moving at 40 kmph. If they stick together, the wreckage now has an initial speed of...
    
    
    
    1. 8 kmph
    2. 40 kmph
    3. 56 kmph
    4. 60 kmph
       
    
    
17. Fluids possess...
    
    
    
    1. only volume elasticity
    2. rigidity and volume elasticity
    3. only rigidity
    4. volume elasticity and tensile elasticity
       
    
    
18. A water-proofing agent...
    
    
    
    1. reduces angle of contact
    2. increases angle of contact
    3. decreases surface tension
    4. increases surface area
       
    
    
19. A certain container holds 1 kg air at atmospheric pressure. When an additional 1 kg of air is pumped into the container at constant temperature, the pressure is...
    
    
    
    1. 0.5 atm
    2. 1 atm
    3. 2 atm
    4. 4 atm
       
    
    
20. If Q is the charge on either of the plates of the capacitor and V is the potential difference across the capacitor with capacitance C, what is not true is...
    
    
    
    1. C = Q/V
    2. V α Q
    3. Q/V = constant
    4. VQ = constant
       
    
    
21. The origin of all magnetic fields lies in...
    
    
    
    1. atoms of iron
    2. magnetic domains
    3. moving charges
    4. permanent magnets
       
    
    
22. The effective atmosphere of sun is called...
    
    
    
    1. photosphere
    2. chromosphere
    3. corona
    4. stratosphere
       
    
    
23. A 4 litre gas cylinder contains neon gas at 12 kPa. Another cylinder with 8 litre capacity is at same temperature and contains argon gas at 24 kPa. When the two are connected, the total pressure will be...
    
    
    
    1. 16 kPa
    2. 18 kPa
    3. 20 kPa
    4. 36 kPa
       
    
    
24. Eddy currents can be of use in...
    
    
    
    1. dynamo armatures
    2. moving coil galvanometers
    3. transformer cores
    4. all of the above.
       
    
    
25. A tube closed at one end and containing air, produces the fundamental note of frequency 512 Hz when excited. If the tube is open at both ends, the fundamental frequency that can be excited in Hz is...
    
    
    
    1. 1024
    2. 512
    3. 256
    4. 128
       
    
    
26. The process by which a heavy nucleus splits into two nuclei is known as...
    
    
    
    1. fusion
    2. β-decay
    3. fission
    4. γ-emission
       
    
    
27. A uniform chain of length L and mass M is lying on a smooth table and one-third of its length is hanging vertically down over the edge of the table. If 'g' is the acceleration due to gravity, the work required to pull the hanging parton to the table is...
    
    
    
    1. MgL
    2. MgL/3
    3. MgL/9
    4. MgL/8
       
    
    
28. Out of the following which is the most elastic ?
    
    
    
    1. rubber
    2. glass
    3. steel
    4. plastic
       
    
    
29. Amagat's isothermal graphs are in the form of...
    
    
    
    1. PV→T
    2. PV→P
    3. P→V
    4. PV→V
       
    
    
30. An ideal heat engine absorbs heat at 127° and rejects heat at 77°. Efficiency of the engine is...
    
    
    
    1. 12.5%
    2. 28%
    3. 68%
    4. 39%