Which of the following statements about the process of melting of a solid are true? The temperature of the solid will

I. remain steady until melting starts.

ll. keep rising until melting starts,

Ill remain steady as melting proceeds.

V, keep rising as melting proceeds.

• A. II and llI only
• B. IlI and IV only
• C. I, Il and Ill only
• D. ll and IV only

The induced current in a coil always flows in a direction so as to oppose the change that causes it. This statement is known as

• A. Coulomb's law
• B. Lenz's law
• C. Faraday's law
• D. Ampere's law

When a brick is taken from the earth's surface to the moon, its mass

• A. remains constant
• B. reduces
• C. increases
• D. becomes zero

A body is projected at an angle of 30° to the horizontal with a velocity of 150 ms\(^{-1.}\). Calculate the time it takes to reach the greatest height [Take g = 10 ms\(^2\) and neglect air resistance]

Which of the following statements best describes the particles in a solid at room temperature? They are

• A. far apart and moving randomly.
• B. close together and vibrating.
• C. close together and stationary.
• D. close together and moving randomly.

When a telescope is in normal use, the final image is at

• A. Infinity
• B. The focus
• C. The radius of curvature
• D. The near point

The correct unit of energy density is?

• A) kg m³ s^-2
• B) kg m² s^-2
• C) kg m^-3 s^-2
• D) kg m^-1 s^-2

Which of the following waves is not mechanical?

• A. Waves in pipes
• B. Water waves
• C. Radio waves
• D. Sound waves

A small metal ball thrown vertically upwards from the top of a tower with an initial velocity of 20ms^-1. If the ball took a total of 6s to reach ground level, determine the height of the tower [g = 10ms^-2]

• A. 60m
• B. 80m
• C. 100m
• D. 120m

The pitch of an acoustic device can be increased by

• A. increasing the frequency
• B. increasing the amplitude
• C. decreasing the loudness
• D. decreasing the intensity