31. The amount of energy required to change a kilogram of ice block into water without a change in temperature is?

- A. specific latent heat of fusion of ice
- B. specific heat capacity of rice
- C. heat capacity of rice
- D. specific heat of vaporization of rice

**32. Which expression gives magnetic flux? **

**33. **The graph of pressure (P) against the reciprocal of the volume (I/V) in Boyles’s law is a?

- A. hyperbola
- B. parabola
- C. curve
- D. straight line

**34. **What quantity of heat is required to convert 20 g of ice at 0 ºC to water at the same temperature? (Specific latent heat of ice = 336 Jg^{−1})

- A. 7.06 x 10
^{3}J - B. 5.38 x 10
^{3}J - C. 6.72 x 10
^{3}J - D. 1.35 x 10
^{3}J

**35. **A train of mass 1600 kg attains a speed of 25 ms^{−1} in 20 seconds. The power developed in the engine is?

- A. 2.5 KW
- B. 80 KW
- C. 25 KW
- D. 50 KW

**36. **The main factor which affects the speed of sound wave is the?

- A. properties of the medium
- B. amplitude of the sound wave
- C. intensity of the sound wave
- D. loudness of the sound wave

**37. **A semiconductor is formed by?

- A. co-ordinate bonds
- B. electrovalent bonds
- C. a substance free of bonds
- D. covalent bonds

**38. **One of the following is a scalar quantity?

- A. weight
- B. momentum
- C. potential energy
- D. moments

**39. **The mercury column in the barometer at notational atmospheric pressure has a height of?

- A. 0.76 cm at see level
- B. 760 cm at sea level
- C. 7.6 cm at sea level
- D. 76 cm at sea level

**40. **If an object just begins to slide on a surface inclined at 30º to the horizontal, the coefficient of friction is?

- A. √3
- B. √3/2
- C. 1/√2
- D. 1/√3