A rainbow is formed due to which of the following phenomena of light?

• (A) Refraction
• (B) Dispersion
• (C) Reflection
• (D) All of these

A particle moves uniformly in a circular path of radius 10 m. It takes 10 s to complete one revolution. Its speed after 20 s will be-

• (A) 1 m/s
• (B) \( 2\pi \) m/s
• (C) 0
• (D) \( \pi \) m/s

The relative density of silver is 10.8. If the density of water is 1000 kg/m³, then the density of silver will be-

• (A) \( 10.8 \times 10^{-3} \) kg/m³
• (B) \( 10.8 \times 10^{3} \) kg/m³
• (C) 10.8 kg/m³
• (D) \( 1.08 \times 10^{-3} \) kg/m³

A boy of mass 50 kg runs with a speed of 4 m/s. His kinetic energy is-

• (A) 40 J
• (B) 4 J
• (C) 400 J
• (D) 0.4 J

In diamond, each carbon atom is bonded to four other carbon atoms forming a:

• (A) Hexagonal structure
• (B) Rigid three-dimensional structure
• (C) Football-shaped structure
• (D) Ring structure

The number of molecules involved in a molecular reaction is called:

• (A) Molecularity
• (B) Order of reaction
• (C) Unimolecular reaction
• (D) Rate of reaction

Which of the following shows an addition reaction?

• (A) \(CH_4\)
• (B) \(C_3H_8\)
• (C) \(C_2H_6\)
• (D) \(C_2H_4\)

The allotrope of carbon that is a good conductor of heat and electricity is:

• (A) Diamond
• (B) Graphite
• (C) Charcoal
• (D) Coal

The rate of a homogeneous reaction is affected by:

• (A) Only temperature
• (B) Only pressure
• (C) Only concentration of reactants
• (D) Temperature, pressure, and concentration of reactants

A particle moves with uniform speed along a circular path. The direction of its acceleration (if any) is-

• (A) Radially outward
• (B) Radially inward
• (C) Tangentially
• (D) No acceleration

\(\tan 1^{\circ} \cdot \tan 2^{\circ} \cdot \tan 3^{\circ} \cdots \tan 89^{\circ} =\)

• (A) 2
• (B) 0
• (C) 3
• (D) 1

If \(\log_{10}3=0.4771,\ \log_{10}7=0.8450\), then the value of \(\log_3 7\) is

• (A) 1.771
• (B) 1.5710
• (C) 1.8460
• (D) 1.6842

(x − y)³ + (y − z)³ + (z − x)³ =

• (A) 3xyz
• (B) (x − y)(y − z)(z − x)
• (C) 3(x − y)(y − z)(z − x)
• (D) 0

If x = 2 + \(\sqrt{3}\), y = 2 − \(\sqrt{3}\), then the value of x⁻³ + y⁻³ is

• (A) 50
• (B) 52
• (C) 45
• (D) 56

The L.C.M. of 7/3, 5/6, 14/9 is

• (A) 70/18
• (B) 70/9
• (C) 70/3
• (D) 70