In the modern-day computers, when operational, the electrical impulses travel _____.

1. 1. At half the speed of light
   2. At the speed of sound
   3. At seven times the speed of sound
   4. Nearly at the speed of light

In a photographic camera fitted with a convex lens, which of the following types of images will be formed on the film?

1. 1. Imaginary and erect
   2. Erect and real
   3. Inverted and real
   4. The type of image formed will depend on the distance between the lens and the object

Echo is the effect produced due to _____.

1. 1. Reflection of sound
   2. Absorption of sound
   3. Refraction of sound
   4. Dispersion of sound

The speed of sound is maximum through which of the following?

1. 1. Water
   2. Wood
   3. Air
   4. Glass

Why does water biol below 100°C at higher altitudes?

1. 1. Water available at higher altitudes is purer than that in the plains
   2. There is lesser dissipation of heat at higher altitudes
   3. The atmospheric pressure at higher altitudes is low compared to that at sea level
   4. Pollution free air at higher altitudes increases the calorific value of fuel used

Why does the mercury column in the barometer fall rapidly before a severe strom?

1. 1. It is due to the fall in atmospheric pressure
   2. It is due to the severe heat energy from the sun
   3. It is due to decrease in humidity in air
   4. It is due to the rise in atmospheric

Springs of shock absorbers of automobiles and railway coaches are made of steel and not of rubber because steel is _____.

1. 1. Less elastic than rubber
   2. More elastic than rubber
   3. More durable than rubber
   4. Less expensive than rubber in the ling run

Surface tension in liquid is due to _____.

1. 1. Electrical for force between the molecules
   2. Adhesive force between the molecules
   3. Cohesive force between the molecules
   4. Gravitational force between the molecules

In T.V. transmission _____.

1. 1. Videos signal is transmitted first, followed by sound signal
   2. Sound and video signals are transmitted from different places at the same time
   3. Sound is transmitted first and then the video signa follows
   4. Sound and video signals are transmitted simultaneously

The hydraulic brakes used in automobiles is a direct application of _____.

1. 1. Pascal’s law
   2. Torricellian law
   3. Bernoulli’s theorem
   4. Archimedes principle