MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 1777 Mcqs, each offering curated multiple-choice questions to sharpen your 9th Class knowledge and support exam preparation. Choose a topic below to get started.
| 901. |
At a place, value of g is less by 1% than its value on the surface of the Earth (Radius of Earth = 6400 km). The place is |
| A. | 64 km below the surface of the Earth |
| B. | 64 km above the surface of the Earth |
| C. | 30 km above the surface of the Earth |
| D. | 32 km below the surface of the Earth. |
| Answer» B. 64 km above the surface of the Earth | |
| 902. |
If a rock is brought from the surface of the moon, |
| A. | Its mass will change |
| B. | Its weight will change but not mass |
| C. | Both mass and weight will change |
| D. | Its mass and weight both will remain same |
| Answer» C. Both mass and weight will change | |
| 903. |
If the distance between the earth and the sun were half its present value, the number of days in a year would have been |
| A. | 64.5 |
| B. | 129 |
| C. | 182.5 |
| D. | 730 |
| Answer» C. 182.5 | |
| 904. |
Assuming earth to be a sphere of uniform mass density, how much would a body weigh half down the centre of the earth, if it weighed 100 N on the surface. |
| A. | 50 N |
| B. | 100 N |
| C. | 25 N |
| D. | 200 N |
| Answer» B. 100 N | |
| 905. |
The depth from the surface of the earth it which the acceleration due to gravity will be 75% of the value on the surface of the earth, (radius of the earth = R) |
| A. | R/4 |
| B. | 3R/4 |
| C. | R/2 |
| D. | R/8 |
| Answer» B. 3R/4 | |
| 906. |
What is the fractional change in the value of freefall acceleration g for a particle when it is lifted from the surface to an elevation h? (\[h |
| A. | \[-2\,\,\left( \frac{R}{h} \right)\] |
| B. | \[\frac{R}{h}\] |
| C. | \[\frac{h}{R}\] |
| D. | \[-2\left( \frac{h}{R} \right)\] |
| Answer» E. | |
| 907. |
Assume that earth is a spherical planet of uniform density\[\rho ,\]radius \[{{R}_{e}},\]mass\[{{M}_{e}}\]and acceleration due to gravity g. Then the gravitational constant G can be written as |
| A. | \[\frac{3}{4\pi \rho {{R}_{e}}}\] |
| B. | \[\frac{gR_{e}^{2}}{{{M}_{e}}}\] |
| C. | \[\frac{3g}{4\pi \rho R_{e}^{2}}\] |
| D. | \[\frac{12\rho g}{4\pi {{R}_{e}}}\] |
| Answer» B. \[\frac{gR_{e}^{2}}{{{M}_{e}}}\] | |
| 908. |
A spherical planet in the space having a mass 'M' and diameter D. A particle of mass m falls freely near the surface of the planet with an acceleration due to gravity which is equal to |
| A. | \[\text{GM}/{{\text{D}}^{\text{2}}}\] |
| B. | \[\text{GMm}/{{\text{D}}^{\text{2}}}\] |
| C. | \[\text{4 GM}/{{\text{D}}^{\text{2}}}\] |
| D. | \[\text{4m GM}/{{\text{D}}^{\text{2}}}\] |
| Answer» D. \[\text{4m GM}/{{\text{D}}^{\text{2}}}\] | |
| 909. |
If the distance between two particles is increased by 2%, then the force of attraction between them will be: |
| A. | Decreases by 6% |
| B. | Decreases by 4% |
| C. | Increases by 4% |
| D. | Increases by 6% |
| Answer» C. Increases by 4% | |
| 910. |
Two metal spheres of same material and radius r are in contact with each other. The gravitational force of attraction between the spheres is proportional to |
| A. | \[{{r}^{4}}\] |
| B. | \[1/{{r}^{3}}\] |
| C. | \[{{r}^{3}}\] |
| D. | \[{{r}^{2}}\] |
| Answer» B. \[1/{{r}^{3}}\] | |
| 911. |
A ball is thrown vertically upwards with a speed of 10 m/s from the top of the tower 200m high and another is thrown vertically downwards with the same speed simultaneously. The time difference between them in reaching the ground is (\[\text{g}=\text{1}0\text{ m}/{{\text{s}}^{\text{2}}}\]) |
| A. | 12s |
| B. | 6s |
| C. | 2s |
| D. | 1s |
| Answer» D. 1s | |
| 912. |
A body thrown up with some initial velocity reaches a maximum height of 50m. Another body with double the mass thrown up with double the initial velocity will reach a maximum height of |
| A. | 100 m |
| B. | 200 m |
| C. | 400 m |
| D. | 50 m |
| Answer» C. 400 m | |
| 913. |
A stone thrown vertically up from the ground reaches a maximum height of 50m in 10s. Time taken by the stone to reach the ground from maximum height is |
| A. | 5s |
| B. | 10s |
| C. | 20s |
| D. | 25s |
| Answer» C. 20s | |
| 914. |
A person standing on the edge of a well throws a stone vertically upwards with an initial velocity \[5\,\,m{{s}^{-1}}.\]The stone gone up, comes down and falls in the well making a sound. If the person hears the sound 3 second after throwing, then the depth of water (neglect time travel for the sound and take \[g=10m{{s}^{-2}}\]) |
| A. | 1.25 m |
| B. | 21.25 m |
| C. | 30 m |
| D. | 32.5 m |
| Answer» D. 32.5 m | |
| 915. |
Acceleration due to gravity is g on the surface of the Earth. Then the value of the acceleration due to gravity at a height of 32 km above Earth's surface is (Radius of the Earth = 6400 km) |
| A. | 0.99 g |
| B. | 0.8 g |
| C. | 1.01 g |
| D. | 0.9 g |
| Answer» B. 0.8 g | |
| 916. |
If the weight of an object when measured inside a coal mine, at the sea level and on the top of a mountain is found to be\[{{w}_{1}},{{w}_{2}}\]and\[{{w}_{3}}\] respectively, then |
| A. | \[{{W}_{1}}>{{W}_{2}}>{{W}_{3}}\] |
| B. | \[{{W}_{1}}={{W}_{2}}={{W}_{3}}\] |
| C. | \[{{W}_{1}}<{{W}_{2}}>{{W}_{3}}\] |
| D. | \[{{W}_{1}}>{{W}_{2}}<{{W}_{3}}\] |
| Answer» D. \[{{W}_{1}}>{{W}_{2}}<{{W}_{3}}\] | |
| 917. |
Taking that Earth revolves round the Sun in a circular orbit of radius\[1.5\times {{10}^{10}}m\]. with a time period of 1 year, the time taken by another planet, which is at a distance of \[\text{54}0\times \text{1}{{0}^{\text{1}0}}\text{ m}\], to revolve round the Sun in circular orbit once will be |
| A. | 216 yrs |
| B. | 144 yrs |
| C. | 72 yrs |
| D. | 36 yrs |
| Answer» B. 144 yrs | |
| 918. |
A bullet is fired horizontally with a velocity 400 m/s from the top of a tower. At the same time a stone is dropped from the same point. Then |
| A. | Stone will reach the ground first |
| B. | Bullet will reach the ground first |
| C. | Both will reach the ground at same time |
| D. | Their times of fall depend on g |
| Answer» D. Their times of fall depend on g | |
| 919. |
A body throws balls vertically upwards. He throws one, while the previous one is at its highest point. Maximum height reached by a ball if he throws one ball each per second at uniform speed is |
| A. | 19.6 m |
| B. | 9.8 m |
| C. | 4.9 m |
| D. | 2.45 m |
| Answer» D. 2.45 m | |
| 920. |
A ball released from a height h touches the ground in t sec. After t/2 s since dropping, the height of the body from the ground |
| A. | h/2 |
| B. | h/4 |
| C. | 3h/4 |
| D. | Depends upon mass and volume of ball. |
| Answer» D. Depends upon mass and volume of ball. | |
| 921. |
A body let fall from the top of a building reaches the ground in 3 s. Height of the building is |
| A. | 14.7 m |
| B. | 24.4 m |
| C. | 44.1 m |
| D. | 66.2 m |
| Answer» D. 66.2 m | |
| 922. |
Two bodies of different masses\[{{m}_{a}}\] and\[{{m}_{b}}\] are dropped from two different heights viz a and b. Ratio of times taken by the two, to drop through these distances is |
| A. | a : b |
| B. | \[\sqrt{b}:\sqrt{a}\] |
| C. | \[\sqrt{a}:\sqrt{b}\] |
| D. | \[{{a}^{2}}:{{b}^{2}}\] |
| Answer» D. \[{{a}^{2}}:{{b}^{2}}\] | |
| 923. |
A body sliding on a smooth inclined plane requires 4s to reach the bottom starting from rest at the top. Time taken by it to cover one fourth of the distance starting from rest at the top is |
| A. | 1 s |
| B. | 2 s |
| C. | 4 s |
| D. | 16 s |
| Answer» C. 4 s | |
| 924. |
The distance of Neptune and Saturn from the Sun are respectively. \[\text{1}{{0}^{\text{13}}}\]and \[\text{1}{{0}^{\text{12}}}\] metres and their periodic times are respectively\[{{T}_{n}}\]and\[{{T}_{s}}\]. If their orbits are assumed to be circular, the value of\[{{T}_{n}}/{{T}_{s}}\]is |
| A. | 100 |
| B. | \[10\sqrt{10}\] |
| C. | \[\frac{1}{10\sqrt{10}}\] |
| D. | 10 |
| Answer» C. \[\frac{1}{10\sqrt{10}}\] | |
| 925. |
The time of revolution of planet A around the sun is 8 times that of another planet B. The distance of planet A from the sun is how many times greater than that of the planet B from the sun? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» D. 5 | |
| 926. |
The time period of a satellite of earth is 5 hrs. If the separation between earth and the satellite is increased to 4 times the previous value, the new time period will become |
| A. | 10 hours |
| B. | 80 hours |
| C. | 40 hours |
| D. | 20 hours |
| Answer» D. 20 hours | |
| 927. |
Two satellites of masses 50 kgs and 100 kgs revolve around the earth in circular orbit of radii 9R and 16R respectively, where 'R' is the radius of the earth. The speeds of the two satellites will be in the ratio |
| A. | 3/4 |
| B. | 4/3 |
| C. | 9/16 |
| D. | 16/9 |
| Answer» C. 9/16 | |
| 928. |
A satellite is launched into a circular orbit of radius "R' around the earth, while a second satellite is launched into an orbit of radius 1.02 R. The percentage difference in the time periods of the two satellites is: |
| A. | 0.7 |
| B. | 1.0 |
| C. | 1.5 |
| D. | 3 |
| Answer» E. | |
| 929. |
An object falls through a distance h in certain time on the earth. The same object falls through a distance 4h in the same time on a planet. If 'g' is acceleration due to gravity on the earth, acceleration due to gravity on that planet is |
| A. | g/4 |
| B. | 4 g |
| C. | g/2 |
| D. | 2 g |
| Answer» B. 4 g | |
| 930. |
Acceleration due to gravity on the surface of a planet is g/5 where g is the value on the earth. When a body is vertically thrown up on the earth, it reaches a maximum height h. If the same body is projected with the same velocity from the surface of planet, maximum height reached by it would be |
| A. | \[h/5\] |
| B. | \[\text{h}/\text{25}\] |
| C. | \[5h\] |
| D. | \[25h\] |
| Answer» D. \[25h\] | |
| 931. |
If the distance between two bodies is increased by 25%, then the % change in the gravitational force is |
| A. | Decreases by 36% |
| B. | Increases by 36% |
| C. | Increases by 64% |
| D. | Decreases by 64% |
| Answer» B. Increases by 36% | |
| 932. |
The period of revolution of a certain planet in an orbit of radius R is T. Its period of revolution in an orbit of radius 4R will be |
| A. | 2 T |
| B. | \[2\sqrt{2}T\] |
| C. | 4 T |
| D. | 8 T |
| Answer» E. | |
| 933. |
The gravitational force between two bodies is decreased by 36% when the distance between them is increased by 3m. The initial distance between them is |
| A. | 6 m |
| B. | 9 m |
| C. | 12 m |
| D. | 15 m |
| Answer» D. 15 m | |
| 934. |
At what height above the earths surface does the acceleration due to gravity fall to 1% of its value at the earths surface? |
| A. | R |
| B. | 5 R |
| C. | 10 R |
| D. | 9 R |
| Answer» E. | |
| 935. |
What will be the acceleration due to gravity on the surface of moon if its radius is\[{}^{1}/{}_{4}\]th the radius of the earth and its mass is\[{}^{1}/{}_{80}\]th the mass of earth? |
| A. | \[\frac{g}{2}\] |
| B. | \[\frac{g}{3}\] |
| C. | \[\frac{g}{7}\] |
| D. | \[\frac{g}{5}\] |
| Answer» E. | |
| 936. |
If a planet existed whose mass and radius both half those of the earth, the acceleration due to gravity at its surface would be |
| A. | \[\text{19}.\text{6 m}/{{\text{s}}^{\text{2}}}\] |
| B. | \[\text{9}.\text{8 m}/{{\text{s}}^{\text{2}}}\] |
| C. | \[\text{4}.\text{9 m}/{{\text{s}}^{\text{2}}}\] |
| D. | \[\text{2}.\text{45 m}/{{\text{s}}^{\text{2}}}\] |
| Answer» B. \[\text{9}.\text{8 m}/{{\text{s}}^{\text{2}}}\] | |
| 937. |
Acceleration due to gravity on the surface of moon is\[\text{1}/{{\text{5}}^{th}}\]that at the surface of the earth. If radius of the moon is\[\text{1}/{{4}^{th}}\]that of the earth, ratio of the mass of the earth to mass of moon is |
| A. | 20 |
| B. | 40 |
| C. | 60 |
| D. | 80 |
| Answer» E. | |
| 938. |
A sphere of mass 40 kg is attrached by another of mass 15 kg when their centres are 0.2 mapart, with a force of\[\text{9}.\text{8}\times \text{l}{{0}^{-\text{7}}}\text{ N}\text{.}\] Calculate the constant of gravitation. |
| A. | \[9.2\times {{10}^{-7}}N{{m}^{2}}k{{g}^{-2}}\] |
| B. | \[6.13\times {{10}^{-11}}N{{m}^{2}}k{{g}^{-2}}\] |
| C. | \[6.53\times {{10}^{-18}}N{{m}^{2}}k{{g}^{-2}}\] |
| D. | \[6.53\times {{10}^{-11}}N{{m}^{2}}k{{g}^{-2}}\] |
| Answer» E. | |
| 939. |
If the force of gravitation between the earth and a body of mass M on its surface be\[\text{9}\times \text{1}0\text{7 N,}\] what would be the value of M? Mass of the earth\[=\text{6}\times \text{1}0\text{24}\,\text{kg}\]. |
| A. | \[\text{9}.\text{2}\times \text{1}{{0}^{\text{3}}}\text{ kg}\] |
| B. | \[\text{9}.\text{2}\times \text{1}{{0}^{5}}\text{ kg}\] |
| C. | \[\text{9}.\text{2}\times \text{1}{{0}^{\text{6}}}\text{ kg}\] |
| D. | \[\text{9}.\text{2}\times \text{1}{{0}^{\text{9}}}\text{ kg}\] |
| Answer» D. \[\text{9}.\text{2}\times \text{1}{{0}^{\text{9}}}\text{ kg}\] | |
| 940. |
Find the gravitational force between two protons kept at a separation of 1 femtometre (1 femtometre\[=\text{1}{{0}^{-\text{15}}}\text{ m}\]). The mass of a proton is\[1.67\times {{10}^{-27}}kg\]. |
| A. | \[1.8\times {{10}^{-42}}N\] |
| B. | \[1.8\times {{10}^{-29}}N\] |
| C. | \[1.8\times {{10}^{-39}}N\] |
| D. | \[1.86\times {{10}^{-34}}N\] |
| Answer» E. | |
| 941. |
g value at a depth \[{}^{R}/{}_{10}\]from the surface of the earth is |
| A. | \[\frac{4g}{5}\] |
| B. | \[\frac{9g}{10}\] |
| C. | \[\frac{g}{10}\] |
| D. | g |
| Answer» C. \[\frac{g}{10}\] | |
| 942. |
If the change in the value of g at a height h above the surface of earth is same as at a depth d below it, then (both d and h being much smaller than the radius of the earth). |
| A. | d = h/2 |
| B. | d = h |
| C. | d = 2h |
| D. | \[\text{d}={{\text{h}}^{\text{2}}}\] |
| Answer» D. \[\text{d}={{\text{h}}^{\text{2}}}\] | |
| 943. |
The depth from the surface of the earth at which the acceleration due to gravity will be 75% of the value on the surface of the earth, (radius of the earth = R) |
| A. | R/4 |
| B. | 3R/4 |
| C. | R/2 |
| D. | R/8 |
| Answer» B. 3R/4 | |
| 944. |
A body weights 63N on the surface of the Earth. At a height h above the surface of Earth, its weight is 28N while at a depth h below the surface of Earth, the weight is 31.5N. The value of h is |
| A. | 0.4 R |
| B. | 0.5 R |
| C. | 0.8 R |
| D. | R |
| Answer» C. 0.8 R | |
| 945. |
If g is acceleration due to gravity on the surface of the earth having radius R, the height above the surface of earth at which the acceleration due to g gravity reducer to\[\frac{g}{2}\]is |
| A. | \[\frac{R}{2}\] |
| B. | \[(\sqrt{2}-1)R\] |
| C. | \[R/\sqrt{2}\] |
| D. | \[\frac{121R}{100}\] |
| Answer» C. \[R/\sqrt{2}\] | |
| 946. |
Find the ratio of weights of a body at heights \[{}^{R}/{}_{2}\] and \[{}^{R}/{}_{3}\]from the surface of the earth (where R is the radius of the earth) |
| A. | \[\frac{3}{2}\] |
| B. | \[\frac{2}{3}\] |
| C. | \[\frac{64}{81}\] |
| D. | \[\frac{1}{2}\] |
| Answer» D. \[\frac{1}{2}\] | |
| 947. |
A man weights W on the surface of Earth. What is the weight at a height equal to R? |
| A. | W |
| B. | W/2 |
| C. | W/4 |
| D. | W/8 |
| Answer» D. W/8 | |
| 948. |
The gravitational force of attraction between two spherical bodies, each of mass 100 kg, if the distance between their centres is 100 m, is |
| A. | \[\text{6}.\text{67}\times \text{1}{{0}^{-\text{11}}}\text{ N}\] |
| B. | \[\text{6}.\text{67}\times \text{1}{{0}^{-\text{9}}}\text{ N}\] |
| C. | 6.67 N |
| D. | \[\text{6}.\text{67}\times \text{1}{{0}^{-4}}\text{ N}\] |
| Answer» B. \[\text{6}.\text{67}\times \text{1}{{0}^{-\text{9}}}\text{ N}\] | |
| 949. |
If R is the radius of the earth, the height above the surface of the earth where the weight of the body is 36% less than its value on the surface of the earth |
| A. | \[\frac{4R}{5}\] |
| B. | \[\frac{R}{5}\] |
| C. | \[\frac{R}{6}\] |
| D. | \[\frac{R}{4}\] |
| Answer» E. | |
| 950. |
If the radius of the earth is 6400 km, the height above the surface of the earth, where the value of acceleration to gravity will be 1 % of the value on the surface of the earth |
| A. | 6400 km |
| B. | 64 km |
| C. | 57600 km |
| D. | 2500 km |
| Answer» D. 2500 km | |