Physics Past Questions and Answers

If the refractive index of a medium is V2, what is the critical angle?

A 45o
B 50o12'
C 56o25'
D 75o
E 90o

Question 212:

In copper plating, a current of 0.5A is allowed for cathode area of 100cm2. If this current is maintained constant for 100 minutes, the thickness of the copper deposited will be approximately (the electrochemical equivalent of copper = 0.0003g/oC, density of copper = 10-4g/cm3 )

A 10-2mm
B 10-3mm
C 10-4mm
D 10-5mm
E 10-6mm

Question 213:

As a positively charge rod is brought nearer to the top cap of a positively charged gold leaf electroscope, the divergence of the leaves will

A Decrease to zero
B Steadily increase
C Decrease to zero and then increase
D Remain constant
E Increase to a maximum and then decrease

Question 214:

Which of the following statements is NOT true of \(\gamma\)-rays?

A \(\gamma\)-rays belong to the electromagnetic spectrum
B \(\gamma\)-rays do not carry an electron charge
C \(\gamma\)-rays obey the inverse cube law in air
D The thickness of aluminium which stops b-particule has a negligible effect on \(\gamma\)-radiation
E The difference between \(\gamma\)-rays and X-rays is that \(\gamma\)-rays originate from energy charges in the nuclei of atoms, while X-rays comes from energy charges associated with the electron structure of atoms

Question 215:

A rocket burns 0.01kg of fuel each second and ejects it as a gas with a velocity of 5,000m/s. What force does the gas exert on the rocket?

A 500,000N
B 500N
C 50N
D 5,000N
E 50,000N