ShilpaFlame Institute

a. It does not become soft on heating under pressure b. it can not be remoulded c. it is either linear or branched chain polymer d. it is cross-linked polymer Ans. c (9)

The acceleration due to gravity near the surface of a planet of radius R and density d is proportional to

(a) d/R2 (b) dR2 (c) dR (d) d/R Answer: c (9)

What will be the acceleration due to gravity at height h if h >> R. Where R is radius of earth and g is acceleration due to gravity on the surface of earth

(a) g/(1 + h/R )2 (b) g ( 1 – 2h/R ) (c) g/( 1- h/R )2 (d) g ( …

Weight of a body is maximum at

(a) Moon (b) Poles of earth (c) Equator of earth (d) Centre of earth Answer: b (5)

A man can jump to a height of 1.5 m on a planet A. What is the height he may be able to jump on another planet whose density and radius are, respectively, one-quarter and one-third that of planet A

(a) 1.5 m (b) 15 m (c) 18 m (d) 28 m Answer: c (4)

The angular speed of earth, so that the object on equator may appear weightless (g = 10 m/s2 , is , radius of earth 6400 km)

(a) 1.25×10-3 rad/sec (b) 1.56 ×10-3 rad/sec (c) 1.25×10-1 rad/sec (d) 1.56 rad/sec Answer: a (4)

Assume that the acceleration due to gravity on the surface of the moon is 0.2 times the acceleration due to gravity on the surface of the earth. If Re is the maximum range of a projectile on the earth’s surface, what is the maximum range on the surface of the moon for the same velocity of projection

(a) 0.2 Re (b) 2 Re (c) 0.5 Re (d) …

If the mass of earth is 80 times of that of a planet and diameter is double that of planet and ‘g’ on earth is 9.8 m/s2 , then the value of ‘g’ on that planet is

(a) 4.9 m/s2 (b) 0.98 m/s2 (c) 0.49 m/s2 (d) 49 m/s2 Answer: c (6)

R and r are the radii of the earth and moon respectively. pe and pm are the densities of earth and moon respectively. The ratio of the accelerations due to gravity on the surfaces of earth and moon is

(a) R/r pe/ pm (b) r/R pe/ pm (c) r/R pe/ pm (d) R/r pe/ pm Answer: a (6)

Assuming earth to be a sphere of a uniform density, what is the value of gravitational acceleration in a mine 100 km below the earth’s surface (Given R = 6400 km)

(a) 9.66 m/s2 (b) 7.64 m/s2 (c) 5.06m/s2 (d) 3.10 m/s2 Answer: a (5)

The angular velocity of the earth with which it has to rotate so that acceleration due to gravity on 60o latitude becomes zero is (Radius of earth = 6400 km. At the poles g=10 ms-2)

(a) 2.5 × 10-3 rad /s (b) 5.0 × 10-1 rad /s (c) 10 × 101 rad /s (d) 7.8 × 10-2 rad /s Answer: a (5)

An object weights 72 N on earth. Its weight at a height of R/2 from earth is

(a) 32 N (b) 56 N (c) 72 N (d) Zero Answer: a (5)

The height of the point vertically above the earth’s surface, at which acceleration due to gravity becomes 1% of its value at the surface is (Radius of the earth = R)

(a) 8 R (b) 9 R (c) 10 R (d) 20 R Answer: b (7)

If the Earth losses its gravity, then for a body

(a) Weight becomes zero, but not the mass (b) Mass becomes zero, but not the weight (c) Both mass and weight become zero (d) Neither mass nor weight become zero Answer: a (7)