How does a lightening conductor protect the buildings?

1. 1. It absorbs the charges released by lightening
   2. It scatters the charge from lightening
   3. It helps the charge to pass into the earth without damaging the building
   4. None of the above

The silvered surface of thermos flask prevents transfer of heat by _____.

1. 1. Radiation
   2. Convection
   3. Conduction
   4. Reflection

Why should a parachute have a hole in it?

1. 1. If there is no hole the parachute will be torn out
   2. While descending, the changing currents may cause oscillation of the parachute; the hole allows the air to run out
   3. If there is no hole, descending is not possible because upward thrust of the air will be balanced with the downward thus pull off the earth
   4. None of the above

When a constant force is applied to a body it moves with uniform _____.

1. 1. Speed
   2. Velocity
   3. Momentum
   4. Acceleration

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

Which one of the following is used as a disinfectant in water treatment?

1. 1. Alum
   2. Kieselguhr
   3. Potassium permanganate
   4. Charcoal

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

The protein content in wheat is approximately _____.

1. 1. 12%
   2. 7%
   3. 8%
   4. 15%