A passenger in a moving train tosses a coin upward which falls behind him. It implies that the motion of the train is

• accelerated

• uniform

• retarded

• along the circular tracks

In optical instruments, the lenses are used to form image by the phenomenon of

• reflection

• refraction

• scattering

• diffusion

A semiconducting device is connected in a series circuit with a battery and a resistance. Current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to zero. The device may be

• p-type semiconductor

• n-type semiconductor

• an intrinsic semiconductor

• p-n junction

If the distance S covered by a moving car in rectilinear motion with a speed v in time t is given by S = vt, then the car undergoes

• a uniform acceleration

• a non-uniform acceleration

• a uniform velocity

• a non-uniform velocity

The phenomenon of electromagnetic induction implies a production of induced

• resistance in a coil when the magnetic field changes with time

• current in a coil when an electric field changes with time

• current in a coil when a magnetic field changes with time

• voltage in a coil when an electric field changes with time

Light waves are

• electro-mechanical waves

• electro-magnetic waves

• electro-optical waves

• magneto-optical waves

A particle is moving in a circular path of radius r at a constant speed v. Which one of the following graphs correctly represents its acceleration a?

208.

Which one of the following circuit elements active component?

• Resistor

• Transistor

• Inductor

• Capacitor

Which one of the following processes explains the splitting of a beam of white light into its constituent colours?

• Dispersion

• Reflection

• Diffraction

• Polarization

Two bodies A and B having masses m and 4m respectively are moving with equal linear momentum. The ratio of kinetic energies between A and B is

• 1 : 4

• 4 : 1

• 1 : 1

• 1 : 2