Questions

The resistance of metallic conductors e.g, platinum, increases with rise of  temperature . The increase in temperature results in a decrease of current which can be recorded in a galvanometer if the conductor is included in an electrical circuit. Thus the temperature can be known; platinum resistance thermometer is used generally for accurate scientific work. When two dissimilar metals are joined at the ends, and these ends are subjected to a difference of temperature, a current flows through the metals. Greater the difference of temperature , greater the current. So the curent strength can form the basis for measuring the difference in temperature. And when one of these temperatures is known, we can calculate the other.

Mass means the amount of matter in an object. Anything that has Mass and takes up Space is called Matter.

The Study of Matter and and how matter changes is called Chemistry.

Matter has some mass and occupies some space. Space occupied by an object is called its Volume.

90 D in RA means 90 Degrees in Right Angle. It is a logic question which is to be eloborated.

Some more of its kind are:

1. 52 W in a Y     -    52 Weeks in a Year

2. 7 C in a R        -    7 Colours in a Rainbow

3. 9 P in SS

4. 5 C in an OF

5. 12 S of the Z

A Clock has a face, but no eyes. It has 3 hands i.e, hours, minutes and seconds hands but no arms.

The Union Territories get representation in Both the houses of Parliament i.e, The Lok Sabha and The Rajya Sabha.

Two series alternate here, with every third number following a different pattern.
In the main series, 4 is added to each number to arrive the next.
In alternate series, 5 is subtracted from each number t arrive the next number.
Here in the main series 
3 + 4 = 7
7 + 4 = 11
11 + 4 = 15
15 + 4 = 19

In alternate series 
24 - 5 = 19
19 - 5 = 14...