Degenerate electron pressure will not be sufficient to prevent core collapse of 'white dwarf' if its mass becomes n times of solar mass. Value of n is:
A. 0.5
B. 0.8
C. 1
D. 1.4
If the earth suddenly stops rotating, the value of g at equator would :
A. decrease
B. remain unchanged
C. increase
D. become zero
The mass of a planet is half that of the earth and the radius of the planet is one-fourth that of earth. If we plan to send an artificial satellite from the planet, the escape velocity will be, (escape velocity on earth ve =11 km- s-1)
A. 11 km-s-1
B. 5.5 km-s-1
C. 15.5 km-s-1
D. 7.78 km-s-1
Two satellites A and B go around the earth in a circular orbits at a height of RA and RB respectively from the surface of the earth. Assume the earth to be a uniform sphere of radius RE. The ratio of magnitudes of the velocities of the statellites VA/VB =
A. √RB/RA
B. RB + RE/(RA +RE)
C. √(RB + RE)/(RA + RE)
D. √RA /RB
A body is projected vertically upwards from the surface of the earth with a velocity equal to half the escape velocity. If R is the radius of the earth, maximum height attained by the body from the surface of the earth is
A. R/6
B. R/3
C. 2R/3
D. R
A gun is aimed at a target in line with its barrel. The target is released and allowed to fall under gravity, at the instant, the gun is fired. The bullet will :
A. pass above the target
B. pass below the target
C. hit the target
D. certainly hit the target
The coefficient of kinetic friction between a body and the surface of an inclined plane at 450 is 0.5. If g = 9.8 ms-2,the acceleration of the body down the inclined plane, in ms-2is:
A. 4.9/√2
B. 4.9
C. 4.9√2
D. 19.6√2