21.

Total internal reflection is possible when light travels from

• air to water

• air to glass

• water to glass

• glass to water

The momentum of a particle having mass m is p. Its kinetic energy will be

• mp

• p²m

• p² /m

• p² / 2m

The potential difference across a conductor of resistivity e is constant. The heat generated in the conductor is directly proportional to

• e

• $\frac{1}{\sqrt{\mathrm{e}}}$

• $\frac{1}{\mathrm{e}}$

• e²

The given logic symbol represents.

• AND gate

• OR gate

• NOT gate

• NAND gate

A body of mass 2 kg is moving on a smooth horizontal surface with an initial velocity of 10 ms^-1 along the east. A uniform force of 10 N towards the north is applied to the body. The final velocity of the body after 2 s will be

• $10\sqrt{2}$ ms^-1 at 45° North of East

• $10\sqrt{2}$ ms^-1 at 45° South of East

• 20 ms^-1 towards East

• 20 ms^-1 towards West

The catalyst used in the Hydrogenation of oil is

• Fe

• Ni

• MO

• Pt

Which of the following gives precipitate, with ammoniacal silver nitrate solution?

• C₂H₆ (Ethane)

• C₂H₄ (Ethylene)

• C₂H₂ (Acetylene)

• C₃H₆ (Propene)

The number of moles in 128 gm of SO₂ will be

• 1 mole

• 2 mole

• 3 mole

• 4 mole

The oxidation state of iron in Fe(CO)₅ is

• 0

• 2

• 3

• 5

The compound responsible for the temporary hardness of water is

• Mg(HCO₃)₂

• CaCl₂

• MgSO₄

• CaCO₃