Advertisements
Advertisements
Calculate the amount of heat energy required to raise the temperature of 200 g of copper from 20°C to 70°C. Specific heat capacity of copper = 390 J kg-1 K-1.
Concept: undefined >> undefined
Draw a ray diagram to show the refraction of a monochromatic ray through a prism when it suffers minimum deviation
Concept: undefined >> undefined
Advertisements
When does the nucleus of an atom tend to become radioactive?
Concept: undefined >> undefined
A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. Compare the effort applied by them. Give a reason to support your answer.
Concept: undefined >> undefined
A pulley system with VR = 4 is used to lift a load of 175 kgf through a vertical height of 15 m. The effort required is 50 kgf in the downward direction. (g = 10 N kg-1)
Calculate:
- Distance moved by the effort
- Work done by the effort
- M.A. of the pulley system
- Efficiency of the pulley system
Concept: undefined >> undefined
Name the radiations which are absorbed by greenhouse gases in the earth’s atmosphere.
Concept: undefined >> undefined
A radiation X is focused by a particular device on the bulb of a thermometer and mercury in the thermometer shows a rapid increase. Name the radiation X
Concept: undefined >> undefined
Answer the following questions based on a hot cathode ray tube
Name the charged particles
Concept: undefined >> undefined
Answer the following questions based on a hot cathode ray tube.
State the approximate voltage used to heat the filament
Concept: undefined >> undefined
Answer the following questions based on a hot cathode ray tube.
What will happen to the beam when it passes through the electric field?
Concept: undefined >> undefined
State three factors on which the rate of emission of electrons from a metal surface depends
Concept: undefined >> undefined
Why do Free electrons not leave the metal surface on their own
Concept: undefined >> undefined
How can they be made to leave the metal surface? (State any two ways)
Concept: undefined >> undefined
State the dependence of angle of deviation On the refractive index of the material of the prism.
Concept: undefined >> undefined
State the dependence of angle of deviation On the wavelength of light
Concept: undefined >> undefined
State the ways by which the frequency of transverse vibrations of a stretch string can be increased
Concept: undefined >> undefined
The music system draws a current of 400 mA when connected to a 12 V battery.
- What is the resistance of the music system?
- The music system if left playing for several hours and finally the battery voltage drops and the music system stops playing when the current drops to 320 mA. At what battery voltage does the music system stop playing?
Concept: undefined >> undefined
An element `""_ZS^A` decays to `""_85R^222` after emitting 2 α particles and 1 β particle.
Find the atomic number and atomic mass of the element S.
Concept: undefined >> undefined
A radioactive substance is oxidized. Will there be any change in the nature its radioactivity? Give a reason for your answer
Concept: undefined >> undefined
