Force and Laws of Motion — Science STD 9 — Question

The atomic numbers of four elements A, B, C and D are 12, 13, 15 and 3 respectively. The element which cannot form a cation is:

1. A
2. B
3. C
4. D

The velocities of sound waves in four media P. Q, R and S are 18,000km/h, 900km/h, 0km/h, and 1200km/h respectively. Which medium could be a liquid substance?

The subatomic particle called electron was discovered by:

Which of these options are not a function of ribosomes?

1. It helps in manufacture of protein molecules.
2. It helps in manufacture of enzymes.
3. It helps in manufacture of hormones.
4. It helps in manufacture of starch molecules.

Which of the following elements does not exhibit the electrovalencey?

If a displacement-time graph of an object is a straight line parallel to the time axis, the object is:

A stone is thrown upwards as shown in the diagram. When it reaches P, which of the following has the greatest value for the stone?

1. Its Acceleration.
2. Its kinetic energy.
3. Its potential energy.
4. Its weight.

Which kind of sound is produced in an earthquake before the main shock wave begins?

1. Ultrasound.
2. Infrasound.
3. Audible sound.
4. None of the above.

The centre for cellular and molecular biology is located at: