Which one of the following devices changes low voltage alternating current to high voltage alternating current and vice-versa?

• Generator

• Motor

• Transformer

• Vibrator

An optical illusion which occurs mainly in deserts during hot summer is based on the principle of

• Reflection

• Interference

• Dispersion

• Total internal reflection

At which place Earth's magnetic field becomes horizontal?

• Magnetic meridian

• Magnetic equator

• Geographical pole

• Tropic of Cancer

The speed of a car travelling on a straight road is listed below at successive intervals of 1s:

0 1 2 3 4 Time (s)
0 2 4 6 8 Speed (m/s)

Which of the following is/are correct?

The car travels
1. with a uniform acceleration of 2 m/s²
2. 16m in 4s
3. with an average speed of 4 m/s.

Select the correct answer using the code given below:

• 1, 2 and 3

• 2 and 3 only

• 1 and 2 only

• 1 only

5.

The speed of a body that has Mach number more than 1 is

• supersonic

• subsonic

• 300 m/s

• about 10 m/s

Molecules of which of the following has cage like structure?

1. Diamond
2. Graphite
3. Fullerenes

Select the correct answer using the code given below:

• 1, 2 and 3

• 2 and 3 only

• 2 only

• 3 only

Temporary hardness in water is due to which one of the following of Calcium and Magnesium?

• Hydrogen carbonates

• Carbonates

• Chlorides

• Sulphates

Stung by hairs of nettle leaves causes burning pain. This is due to the injection of

• Acetic acid

• Methanoic acid

• Sulphuric acid

• Hydrochloric acid

Which one of the following elements is least reactive with water?

• Lithium

• Sodium

• Potassium

• Cesium

Rutherford's alpha-particle scattering experiment was responsible for the discovery of

• Electron

• Proton

• Nucleus

• Helium