Free MCQs & Online Quiz Practice for Exams

Q: The transfer of heat by convection is smallest in

A) Solids

B) Liquids

C) Gases

D) None

Q: One way that heat is transferred from place to place in the body is by the flow of blood. Which process best describes this action?

A) Convection

B) Conduction

C) Radiation

D) None

Q: The best absorber of radiation is a body whose surface is

A) White

B) Grey

C) Dull black

D) Highly polished

Q: The mode of transfer of heat which does not require a material medium is called

A) Convection

B) Conduction

C) Radiation

D) None

Q: Which of the following has the highest thermal conductivity?

A) Water

B) Wood

C) Wool

D) Air

Q: The temperature at which a body is not radiating any heat is

A) 0°C

B) 0°F

C) 0 K

D) All of these

Q: The electrons that are free to move through the metal are called

A) Lose electrons

B) Free electrons

C) Conduction electrons

D) Holes

Q: Work done will be zero when the angle between force and displacement is

A) 30°

B) 45°

C) 60°

D) 90°

Q: A 30 N force is exerted and the trolley moves a distance of 5 m in the direction of the force. The work done is

A) 6 J

B) 25 J

C) 150 J

D) 0.17 J

Q: If the speed of a car decreases by half, the kinetic energy changes by factor

A) 4

B) 2

C) 1/2

D) 1/4

Q: An object of mass 10 kg is lifted vertically through a height of 5 m. The gravitational potential energy gained by the object is

A) 0.5 J

B) 2 J

C) 50 J

D) 490 J

Q: If a petrol engine does 20 J of useful work for every 100 J of energy supplied to it, then its efficiency is

A) 80%

B) 60%

C) 40%

D) 20%

Q: KWh is a unit for

A) Energy

B) Power

C) Efficiency

D) None

Q: 1 horsepower (hp) =

A) 476 W

B) 550 W

C) 746 W

D) 1 ft·lb/s

Q: Hira weighing 500 N takes 90 s to reach the top of a hill 18 m high. Her average muscle power is

A) 2500 W

B) 100 W

C) 32.8 W

D) 3.24 W

Q: A machine lifts a 200 N concrete slab vertically to a height of 30 m above the ground in 50 s. The average power of the machine is

A) 1.33 W

B) 60 W

C) 120 W

D) 6000 W

Q: Which one of the following is a substitution reaction?

A) Halogenation of alkynes

B) Halogenation of alkanes

C) Halogenation of alkenes

D) Oxidation of alkene

Q: Dehydrohalogenation of alkyl halide is

A) Removal of hydrogen

B) Removal of halogen

C) Removal of hydrogen and halogen

D) Addition of hydrogen and halogen

Q: Which one of the following decolourises Br₂ water?

A) Ethane

B) Ethene

C) Ethyne

D) Propane

Q: The general formula of alkanes is

A) CnH₂n

B) CnH₂nₓ₂

C) CnH₂n₊₂

D) CH₂nₓ₂