What factors determine the frequency of a note emitted by a vibrating string?

• A. Amplitude of vibration, force constant of string and length of string
• B. Amplitude of vibration, force constant of string, and tension in string
• C. Mass per unit length of string, tension in string and length of string
• D. Force constant of string, tension in string, and length of string.

A dry plastic comb used in combing hair was found to attract pieces of paper and dust. The most probable explanation for this phenomenon is that the comb has been given

• A. magnetization by induction
• B. electric charges by induction
• C. electric charges by conduction
• D. electric charges by friction

Presbyopia is a defect of the eye resulting from

• A. weak ciliary muscles
• B. short eyeball
• C. loss of sphericity of the lens
• D. long eyeball

A charge 50 µc has electric field strength of 360 NC^-1 at a certain point. The electric field strength due to another charge 120 µc kept at the same distance apart and in the same medium is?

• A) 864 NC-1
• B) 150 NC-1
• C) 144 NC-1
• D) 18 NC-1

Calculate the escape velocity of a satellite launched from the earth's surface if the radius of the earth is 6.4x10⁶m

• A. 25.3kms^-1
• B. 4.2kms^-1
• C. 4.0kms^-1
• D. 11.3kms^-1

State:

(a) The S.I. unit of the intensity of a blackbody radiation.

(b) Two features of the intensity-wavelength graph of a perfect blackbody at different temperatures.

The mass of a specific gravity bottle is 15.2g when it is empty. it is 24.8g when filled with kerosene and 27.2g when filled with distilled water. Calculate the relative density of kerosene

• A. 1.25
• B. 1.10
• C. 0.90
• D. 0.80

If the stress on a wire is 107NM^−2 and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The young's modulus of the wire is?

• A. 5.0 x 10⁻⁴Nm⁻²
• B. 5.0 x 10⁻⁵Nm⁻²
• C. 2.0 x 10⁻⁸Nm⁻²
• D. 2.0 x 10⁹Nm⁻²

The physical quantity that has the same dimensions as impulse is

• A. energy
• B. momentum
• C. surface tension
• D. pressure

Which of the following electromagnetic wave has the longest wavelength?

• A. radio-waves
• B. gamma rays
• C. infrared waves
• D. ultraviolet rays