Answer briefly.
Give two uses of radio waves.
Concept: Electromagnetic Spectrum
Answer the following question.
Under what conditions are total internal reflection possible? Explain it with a suitable example.
Concept: Total Internal Reflection
The distance between two bodies is doubled. How is the magnitude of the gravitational force between them affected?
Concept: Centre of Gravity
Define emissive power and coefficient of emmision of a body.
Concept: Heat and Temperature
Two copper spheres of radii 6 cm and 12 cm respectively are suspended in an evacuated enclosure. Each of them are at a temperature 15°C above the surroundings. The ratio of their rate of loss of heat is.................
- 2:1
- 1:4
- 1:8
- 8:1
Concept: Heat and Temperature
The dimensions of emissive power are
Concept: Heat and Temperature
A pinhole is made in a hollow sphere of radius 5 cm whose inner wall is at temperature 727oC. Find the power radiated per unit area. [Stefan’s constant σ = 5.7 x 10-8 J/m2 s K4 , emissivity (e) = 0.2]
Concept: Heat and Temperature
Compute the temperature at which the r.m.s. speed of nitrogen molecules is 832 m/s. [Universal gas constant, R = 8320 J/k mole K, molecular weight of nitrogen = 28.]
Concept: Heat and Temperature
The light from the Sun is found to have a maximum intensity near the wavelength of 470 nm. Assuming the surface of the Sun as a black body, the temperature of the Sun is _____________.
[Wien's constant b = 2 .898 x l0- 3mK]
Concept: Heat and Temperature
A metal ball cools from 64 °C to 50 °C in 10 minutes and to 42 °C in next 10 minutes. The ratio of rates of fall of temperature during the two intervals is _______.
Concept: Heat and Temperature
The susceptibility of magnesium at 300 K is 2.4 x 10-5. At what temperature will the susceptibility increase to 3.6 x 10-5?
Concept: Heat and Temperature
1000 tiny mercury droplets coalesce to form a bigger drop. In this process, temperature of the drop _______ .
(A) increases
(B) may increase or decrease
(C) decreases
(D) does not change
Concept: Heat and Temperature
A body cools from 62°C to 54°C in 10 minutes and to 48°C in the next 10 minutes. Find the temperature of the surroundings.
Concept: Heat and Temperature
The susceptibility of magnesium at 300K is 1.2 x 10-5. At what temperature will the susceptibility increase to 1.8 X 10-5?
Concept: Heat and Temperature
The substance which allows heat radiations to pass through is _______.
(A) iron
(B) water vapour
(C) wood
(D) dry air
Concept: Heat and Temperature
Explain: ‘How is a rainbow formed’?
Concept: Some Natural Phenomena Due to Sunlight
| Maharashtra State Board HSC Science (Electronics) 11th Standard Important Questions |
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| Important Questions for Maharashtra State Board HSC Science (Electronics) 11th Standard Mathematics and Statistics |
| Important Questions for Maharashtra State Board HSC Science (Electronics) 11th Standard Physics |
