May, 2022Flame Institute

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Spirogyra cells contain

(a) One chloroplast and one pyrenoid (b) One or more chloroplast, each with one pyrenoid (c) One or more chloroplast, each with many pyrenoids (d) None of the above Ans. c (9)

A satellite is moving around the earth with speed v in a circular orbit of radius r. If the orbit radius is decreased by 1%, its speed will

(a) Increase by 1% (b) Increase by 0.5% (c) Decrease by 1% (d) Decrease by 0.5% Answer: b (4)

Out of the following, the only incorrect statement about satellites is

(a) A satellite cannot move in a stable orbit in a plane passing through the earth’s centre (b) Geostationary satellites are launched in the equatorial plane (c) We can use just one geostationary satellite for global communication around the globe …

Choose the correct statement from the following : The radius of the orbit of a geostationary satellite depends upon

(a) Mass of the satellite, its time period and the gravitational constant (b) Mass of the satellite, mass of the earth and the gravitational constant (c) Mass of the earth, mass of the satellite, time period of the satellite and …

If the height of a satellite from the earth is negligible in comparison to the radius of the earth R, the orbital velocity of the satellite is

(a) gR (b) gR/2 (c) √g/R (d) √gR Answer: d (3)

In a satellite if the time of revolution is T, then K.E. is proportional to

(a) 1/T (b) 1/T2 (c) 1/T3 (d) T-2/3 Answer: d (31)

The orbital velocity of an artificial satellite in a circular orbit just above the earth’s surface is v. For a satellite orbiting at an altitude of half of the earth’s radius, the orbital velocity is

(a) 3/2 v (b) √(3/2) v (c) √(2/3) v (d) 2/3 v Answer: c (5)

Which of the following is a nitrogen fixer

(a) Ulothrix (b) Anabaena (c) Ulva (d) Hydrodictyon Ans. b (11)

Which of the following is a flagellated alga

(a) Chlamydomonas (b) Ulothrix (c) Spirogyra (d) Acetabularia Ans. a (11)

The pigment phycoerythrin is characteristic of

(a) Green algae (b) Brown algae (c) Red algae (d) Blue green algae Ans. c (8)

26. Two identical satellites are at R and 7R away from earth surface, the wrong statement is (R = Radius of earth)

(a) Ratio of total energy will be 4 (b) Ratio of kinetic energies will be 4 (c) Ratio of potential energies will be 4 (d) Ratio of total energy will be 4 but ratio of potential and kinetic energies will …

27. For a satellite escape velocity is 11 km/s. If the satellite is launched at an angle of 60° with the vertical, then escape velocity will be

(a) 11 km/s (b) 11√ 3 km/s (c) 11/√3 km/s (d) 33 km/s Answer: a (6)

15. Assertion : The apparent weight of a body in an elevator moving with some downward acceleration is less than the actual weight of body. Reason : The part of the weight is spent in producing downward acceleration, when body is in elevator.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. (b) If both assertion and reason are true but reason is not the correct explanation of the assertion. (c) If assertion is …

14. Assertion : A rocket works on the principle of conservation of linear momentum. Reason : Whenever there is a change in momentum of one body, the same change occurs in the momentum of the second body of the same system but in the opposite direction.

13. Assertion : A bullet is fired from a rifle. If the rifle recoils freely, the kinetic energy of rifle is more than that of the bullet. Reason : In the case of rifle bullet system the law of conservation of momentum violates.

12. Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : Force required to move a body uniformly along a straight line is zero.

11. Assertion : The work done in bringing a body down from the top to the base along a frictionless incline plane is the same as the work done in bringing it down the vertical side. Reason : The gravitational force on the body along the inclined plane is the same as that along the vertical side.

10. Assertion : A cyclist always bends inwards while negotiating a curve. Reason : By bending, cyclist lowers his centre of gravity.

If the angular speed of the earth is doubled, the value of acceleration due to gravity (g) at the north pole

(a) Doubles (b) Becomes half (c) Remains same (d) Becomes zero Answer: C (59)

Spot the wrong statement :The acceleration due to gravity ‘g’ decreases if

(a) We go down from the surface of the earth towards its centre (b) We go up from the surface of the earth (c) We go from the equator towards the poles on the surface of the earth (d) The …

At the surface of a certain planet, acceleration due to gravity is one-quarter of that on earth. If a brass ball is transported to this planet, then which one of the following statements is not correct

(a) The mass of the brass ball on this planet is a quarter of its mass as measured on earth (b) The weight of the brass ball on this planet is a quarter of the weight as measured on earth …

At what altitude in metre will the acceleration due to gravity be 25% of that at the earth’s surface (Radius of earth = R metre)

(a) 1/4 R (b) R (c) 3/8 R …

60. We have two spheres, one of which is hollow and the other solid. They have identical masses and moment of inertia about their respective diameters. The ratio of their radius is given by

(a) 5:7 (b) 3:5 (c) √3:√5 (d) √3:√7 Ans. c (8)

R is the radius of the earth and ω is its angular velocity and gp is the value of g at the poles. The effective value of g at the latitude λ = 60° will be equal to

(a) gp – 1/4 Rω2 (b) gp – 3/4 Rω2 (c) gp – Rω2 (d) gp + 1/4 Rω2 Answer: …

The diameters of two planets are in the ratio 4 : 1 and their mean densities in the ratio 1 : 2. The acceleration due to gravity on the planets will be in ratio

(a) 1 : 2 (b) 2 : 3 (c) 2 : 1 (d) 4 : 1 Answer: …

At what height over the earth’s pole, the free fall acceleration decreases by one percent (assume the radius of earth to be 6400 km)

(a) 32 km (b) 80 km (c) 1.253 km (d) 64 km Answer: a …

The depth d at which the value of acceleration due to gravity becomes 1/n times the value at the surface, is [R = radius of the earth]

(a) R/N (b) R ( n-1/n ) (c) R/n2 …

The moon’s radius is 1/4 that of the earth and its mass is 1/80 times that of the earth. If g represents the acceleration due to gravity on the surface of the earth, that on the surface of the moon is

(a) g/4 (b) g/5 (c) g/6 (d) g/8 Answer: b (4)

If the earth suddenly shrinks (without changing mass) to half of its present radius, the acceleration due to gravity will be

(a) g/2 (b) 4g (c) g/4 (d) 2g Answer: b (10)

If the earth rotates faster than its present speed, the weight of an object will

(a) Increase at the equator but remain unchanged at the poles (b) Decrease at the equator but remain unchanged at the poles (c) Remain unchanged at the equator but decrease at the poles (d) Remain unchanged at the equator but …

Choose the correct statement from the following : Weightlessness of an astronaut moving in a satellite is a situation of

(a) Zero g (b) No gravity (c) Zero mass (d) Free fall Answer: d (3)

The value of g on the earth’s surface is 980 cm /sec2 . Its value at a height of 64 km from the earth’s surface is

(a) 960.40 cm/sec2 (b) 984.90 cm/sec2 (c) 982.45 cm/sec2 (d) 977.55 cm/sec2 (Radius of the earth R …

A spring balance is graduated on sea level. If a body is weighed with this balance at consecutively increasing heights from earth’s surface, the weight indicated by the balance

(a) Will go on increasing continuously (b) Will go on decreasing continuously (c) Will remain same (d) Will first increase and then decrease Answer: b (9)

Which of the following statements is true

(a) g is less at the earth’s surface than at a height above it or a depth below it (b) g is same at all places on the surface of the earth (c) g has its maximum value at the …