Which of the following causes adiabatic temperature changes in atmosphere?
Sound waves cannot travel through a
Which of the following statements is/are correct?
1. There is no net moment on a body which is in equilibrium
2.The momentum of a body is always conserved
3.The kinetic energy of an object is always conserved
Working of safety fuses depends upon
1. Magnetic effect of the current
2. Chemical effect of the current
3. Magnitude of the current
4. Heating effect of the current
The frequency of ultrasound waves is:
Which of the following statements about visible light, UV light and X-rays is/are correct?
1. The wavelength of visible light is more than that of X-rays.
2. The energy of X-ray photons is higher than that of UV light photons.
3. The energy of UV light photons is less than that of visible light photons.
The connecting cable of electrical appliances like electric iron, water heater or room heater contains three insulated copper wires of three different colours-red, green and black. Which one of the following is the correct colour code ?
Which of the following statements about a microscope and a telescope is/are correct ?
1. Both the eyepiece and the objective of a microscope are convex lenses.
2. The focal length of the objective of a telescope is larger than the focal length of its eyepiece.
3. The magnification of a telescope increases with the increase in focal length of its objective.
4. The magnification of a microscope increases with the increase in focal length of its objective.
Which one of the following statements about the law of conservation of mass is correct ?
Which one of the following statements is correct for a plane mirror?