Which of the following metals is used in aircraft?

1. 1. Titanium
   2. Chromium
   3. Palladium
   4. All of these

In electric fittings, the wires are earthed because _____.

1. 1. In case of a short circuit, current passes to the earth
   2. It completes the electric circuit
   3. It reduces fluctuation
   4. It avoid leakage of electricity

Sound travels with a different speed in different medial. In what order does the velocity of sound increase in these media?

1. 1. Iron, air and water
   2. Water, iron and air
   3. Air, water and iron
   4. Iron, water and air

Four identical kettles with the same amount of water, have bases made of different metals of the same thickness. If these are placed on identical flames water will boil first in the kettle with a base made of _____.

1. 1. Copper
   2. Aluminum
   3. Steel
   4. brass

The nucleus of an atom consists of _____.

1. 1. Only proton
   2. Protons and neutrons
   3. Protons + Electrons
   4. Proton + Neutron + Electron

A molecule is _____.

1. 1. The spectrum of a substance
   2. A small mass
   3. The smallest unit of a substance that retains the properties of the substance
   4. A class of organic compunds

A fuse wire is used to _____.

1. 1. Prevent an unduly high electric current to pass through a circuit
   2. Convert AC into DC
   3. Convert DC into AC
   4. To make the electrical circuit strong

In an earthen pot cooling of water depends upon _____.

1. 1. Wind
   2. Outside temperature
   3. Atmospheric humidity
   4. Galvanometer

Food is cooked quickly in a pressure cooker because _____.

1. 1. It absorbs heat quickly
   2. It retains heat for a long duration
   3. Boiling point of water id decreased
   4. Boiling point of water is increased

Fish plates are used in railway tracks _____.

1. 1. To connect two rails
   2. To control speed of the train
   3. To avoid tracks being distorted due to temperature fluctuation
   4. To keep the rails equidistant