On which principle does the tape-recorder function?

1. 1. Boyle’s Law
   2. Electro valency
   3. Gay Loussac’s law of combining volumes
   4. Electromagnetic Induction

Conductors, insulators and semi-conductors differ from each other due to property of _____.

1. 1. formation of crystal lattice
   2. mutual width of their energy gaps
   3. ability of the current they carry
   4. binding energy of their electrons

Choke coil is a coil of _____.

1. 1. Low resistance and high inductance
   2. Low resistance and low inductance
   3. High resistance and high inductance
   4. High resistance and law inductance

The tendency of a liquid drop to contract and occupy minimum area is due to _____.

1. 1. Density
   2. Vapor Pressure
   3. Viscosity
   4. Surface tension

Which of the following is a good conductor of electricty?

1. 1. Glass
   2. Graphite
   3. PVC
   4. Rubber

Which one of the following can be used to focus sunlight?

1. 1. Plane mirror
   2. Concave lens
   3. Concave mirror
   4. Convex mirror

Which one of the following colors has the longest wavelength?

1. 1. Green
   2. Yellow
   3. Blue
   4. Red

Ice floats on water because the density of ice is less than that of water. Out of the following what part of giant icebergs remains above water?

1. 1. 1/10
   2. 1/4
   3. 1/2
   4. 3/4

Which one of the following sets of properties are relevant for an electrical fuse wire needed for normal application?

1. 1. Thick wire, high melting point alloy, short length
   2. Thick wire, low melting point alloy, large length
   3. Short length, low melting point alloy, thin wire
   4. Large length, low melting point alloy, thin wire

The blue color of the sky can be attributed to _____.

1. 1. Differential scattering of sunlight by the atmosphere
   2. Total internal reflection of the sunlight by the atmosphere
   3. Absorption of sunlight
   4. Refraction of sunlight by the atmosphere