- 1(current)
Q. No.1. X-rays
2. Infrared rays
3. Ultraviolet rays
4. \(\gamma\)-rays
The condition under which a microwave oven heats up a food item containing water molecules most efficiently is:
| 1. | the frequency of microwaves has no relation with the natural frequency of water molecules. |
| 2. | microwaves are heatwaves, so always produce heating. |
| 3. | infrared waves produce heating in a microwave oven. |
| 4. | the frequency of the microwaves must match the resonant frequency of the water molecules. |
| 1. | gamma rays, ultraviolet, infrared, microwaves. |
| 2. | microwaves, gamma rays, infrared, ultraviolet. |
| 3. | infrared, microwave, ultraviolet, gamma rays. |
| 4. | microwave, infrared, ultraviolet, gamma rays. |
If \(\lambda_{v}, \lambda_{x},\) and \(\lambda_{m}\) represent the wavelengths of visible light, \(x\text-\)rays and microwaves respectively, then:
1. \( \lambda_{m}>\lambda_{x}>\lambda_{v} \)
2. \( \lambda_{v}>\lambda_{m}>\lambda_{x } \)
3. \( \lambda_{v}>\lambda_{x}>\lambda_{m }\)
4. \(\lambda_{m}>\lambda_{v}>\lambda_{x}\)
Which of the following has the minimum wavelength?
1. \(X\text-\)rays
2. Ultraviolet rays
3. \(\gamma\text-\)rays
4. Cosmic rays
What is the cause of “Greenhouse effect”?
1. Infra-red rays
2. Ultraviolet rays
3. \(X\text-\)rays
4. Radio waves
The biological importance of the ozone layer is:
| 1. | it stops ultraviolet rays. |
| 2. | ozone layer reduces the greenhouse effect. |
| 3. | ozone layer reflects radio waves. |
| 4. | ozone layer controls \(\mathrm{O}_2 / \mathrm{H}_2\) ratio in the atmosphere. |
| 1. | \( b>a>c \) | 2. | \( a>b>c \) |
| 3. | \( c>b>a \) | 4. | \( a>c>b\) |
- 1(current)
Q. No.
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