MCQ : Set #2

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

1. In a tug-of-war match, one team is pulling with a force of 500 N. If they are exactly balanced by the other team, then the tension in the rope is...
   
   
   
   1. 0
   2. 250 N
   3. 500 N
   4. 1000 N
      
   
   
2. The time taken by the light to travel from Sun to earth is approximately...
   
   
   
   1. 8 seconds
   2. 8 minutes
   3. 18 seconds
   4. 18 minutes
      
   
   
3. A charge q is placed at the centre of the line joining two equal charges Q. The system of the three charges will be in equilibrium if q is equal to...
   
   
   
   1. -(Q/2)
   2. -(Q/4)
   3. +(Q/4)
   4. +(Q/2)
      
   
   
4. The velocity of sound in vacuum is 320 m/s. A pipe closed at one end has a length 1 m. Neglecting end corrections, the air column in the pipe can resonate for sound of frequency which is not equal to...
   
   
   
   1. 80 Hz
   2. 240 Hz
   3. 320 Hz
   4. 400 Hz
      
   
   
5. The thermodynamic coordinate that remains constant during an adiabatic process is...
   
   
   
   1. temperature
   2. pressure
   3. density
   4. entropy
      
   
   
6. _____ is not contained in the nucleus of an atom...
   
   
   
   1. proton
   2. electron
   3. neutron
   4. meson
      
   
   
7. As an airplane climbs...
   
   
   
   1. its mass decreases
   2. its mass increases
   3. its weight decreases
   4. its weight increases
      
   
   
8. The unit of the force constant is...
   
   
   
   1. Nm
   2. Nm²
   3. Nm^-2
   4. Nm^-1
      
   
   
9. Brownian motion increases as...
   
   
   
   1. the particle size increases
   2. the particle size decreases
   3. the viscosity of the medium increases
   4. the temperature decreases.
      
   
   
10. Young's modulus is associated with...
    
    
    
    1. volume elasticity
    2. rigidity
    3. shear elasticity
    4. tensile elasticity
       
    
    
11. The force of adhesion is greater than the force of cohesion. This means that the angle of contact (θ) is equal to...
    
    
    
    1. 180°
    2. 120°
    3. 90°
    4. 45°
       
    
    
12. The temperature of an object is raised by 50°C. This is equivalent to an increase in its absolute temperature of...
    
    
    
    1. 50 K
    2. 323 K
    3. 223 K
    4. 82 K
       
    
    
13. The total electric flux is...
    
    
    
    1. always positive
    2. always negative
    3. always zero
    4. none of the above
       
    
    
14. If the field lines are evenly spaced, the field is...
    
    
    
    1. uniform
    2. zero
    3. strong
    4. weak
       
    
    
15. Relative to its object, a real image formed by a lens is always...
    
    
    
    1. erect
    2. inverted
    3. smaller
    4. larger
       
    
    
16. The highest proportion of gas in the Sun is that of...
    
    
    
    1. hydrogen
    2. helium
    3. carbon dioxide
    4. carbon monoxide
       
    
    
17. The product of the period and frequency of a harmonic oscillation is always equal to...
    
    
    
    1. 1
    2. π
    3. 2π
    4. A
       
    
    
18. A direct result of superposition of waves is...
    
    
    
    1. resonance
    2. a wavefront
    3. a progressive wave
    4. beating
       
    
    
19. In the absence of external force the velocity of the center of mass of a system of particles is...
    
    
    
    1. zero
    2. constant
    3. maximum
    4. minimum
       
    
    
20. Three particles of masses 1 kg, 2 kg and 1 kg are at the points whose position vectors are i + j, 2i - j and 3i + j, respectively. The position vector of their centre of mass is...
    
    
    
    1. (6i + j)/4
    2. 2i
    3. (6i + j)/3
    4. 8i
       
    
    
21. For an object above 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
       
    
    
22. A perfectly reversible process...
    
    
    
    1. exists
    2. does not exist but is possible
    3. is impossible
    4. involves intermediate inequilibrium states
       
    
    
23. The unit of resistance is...
    
    
    
    1. volt/second
    2. ampere/second
    3. volt.ampere
    4. volt/ampere
       
    
    
24. The unit of magnetic flux density is...
    
    
    
    1. weber
    2. tesla
    3. henry
    4. faraday
       
    
    
25. The power factor of a circuit is equal to...
    
    
    
    1. RZ
    2. R/Z
    3. X_L/Z
    4. X_L/Z
       
    
    
26. Ozone layer absorbs all electromagnetic radiations having wavelength...
    
    
    
    1. smaller than 3 x 10^-7 m
    2. smaller than 3 x 10^-8 m
    3. greater than 3 x 10^-7 m
    4. greater than 3 x 10^-8 m
       
    
    
27. Stationary waves are produced by...
    
    
    
    1. interference
    2. diffraction
    3. polarization
    4. refraction
       
    
    
28. According to Planck's quantum theory, the emission of energy...
    
    
    
    1. is continuous
    2. is discontinuous
    3. does not depend on wavelength
    4. does not depend on frequency
       
    
    
29. When an electron jumps from an orbit of higher energy E₂ to the one with lower energy E₁, the frequency of the electromagnetic radiation emitted depends on...
    
    
    
    1. E₂
    2. E₁
    3. E₁ + E₂
    4. E₂ - E₁
       
    
    
30. After 10 years 75 g of an original sample of 100 g of a certain radioactive element has decayed. The half-life of the isotope is...
    
    
    
    1. 5 years
    2. 7.5 years
    3. 20 years
    4. 40 years