If the momentum of a body increases from 10 units to 25 units in 5 sec, then the force acting on it is
1 unit
2 units
3 units
4 units
Mica is used in cooking utensils because it is
good conductor of heat but bad conductor of electricity
bad conductor of heat but good conductor of electricity
good conductor of both heat and electricity
bad conductor of both heat and electricity
The angle of dip at magnetic pole of earth is
0°
45°
90°
135°
C.
90°
The angle between the total earth magnetic field and surface of the earth is known as angle of dip.Magnetic field of the magnetic pole of the earth is vertical. Thus angle (dip) made by total magnetic field with the surface of the earth is 90°.
Sound waves consist of 20 compressions and 20 rarefactions in 10m length. The wavelength of the waves is
25cm
50cm
75cm
100cm
If and be respectively the absolute refractive indices of water and glass, then the refractive index of glass relative to water is
Which of the following is not a constituent of petroleum?
Petrol
Coke
Paraffin wax
Lubricating oil
A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M.
Na
Mg
Cu
Ca