Physics - Study Mode

[#991] Instruments for measuring Solar Radiation?
Correct Answer

(B) Pyranometer

Explanation

Solution: Instruments for measuring Solar Radiation is Pyranometer.

[#992] The dimensional formula for universal gravitational constant is
Correct Answer

(D) M –1 L 3 T –2

Explanation

Solution: The gravitational constant is dimensionally represented as M -1 L 3 T -2 .

[#993] Which one of the following physical quantities has the same dimensions as that of Planck's constant?
Correct Answer

(B) Angular momentum

Explanation

Solution: Angular momentum has the same dimensions as that of Planck's constant.

[#994] Period of oscillation of 3 cm microwaves in seconds is
Correct Answer

(B) 1 × 10 –10

Explanation

Solution: The period of oscillation of 3 cm microwaves is 1 × 10 -10 (Physics, Volume 1, by Halliday). The period of oscillation is the smallest interval of time in which a system undergoing oscillation returns to the state it was in at the beginning of the oscillation.

[#995] When a person sitting on a swing stands up on the swing, the frequency of oscillation
Correct Answer

(B) Increases

Explanation

Solution: In Simple Harmonic Motion, the frequency of the oscillation (f) is the number of oscillations per second
which is expressed as f = 1 / T where T is the time period (the time for the oscillator to complete one cycle). Now, when a person sitting on a swing stands up on the swing, the effective length of the swing decreases. When length decreases, the time period also decreases. Since frequency of oscillation is inversely proportion to time period, it increases in the present case of man standing up on the swing.