138236
Three particles each of mass $m$ are kept at vertices of an equilateral triangle of side $L$. The gravitational field at centre due to these particles is
A In equilateral triangle all sides are equal i.e. $\mathrm{AB}=\mathrm{BC}=$ $\mathrm{CA}$ and the line joining the centre of gravity to each vertex of the triangle are each at angle $120^{\circ}$ and gravitational field by each mass will be along these lines joining the centre and vertex. As triangle is equilateral, then the gravitational field produced by each mass will be same. Gravitational field produced is equal in magnitude and at an angle $120^{\circ}$. So, net field will be zero.
Manipal UGET-2010
Gravitation
138244
A satellite orbiting around the certain planet has apogee $R_{1}$ and perigee equal to $R_{2}$, then find the minimum kinetic energy that should be given to the satellite to enable it to escape from the planet.
C $\stackrel{\mathrm{R}_{1} \rightarrow}{*} \leftarrow \mathrm{R}_{2} \rightarrow$ $\mathrm{r}=\mathrm{R}_{1}+\mathrm{R}_{2}$ $\because \quad$ T. E. $=\frac{-\mathrm{GMm}}{2 \mathrm{r}}$ K. $\mathrm{E}=\mid$ T. E. $|=|-\frac{\mathrm{GMm}}{2 \mathrm{r}} \mid=\frac{\mathrm{GMm}}{2\left(\mathrm{R}_{1}+\mathrm{R}_{2}\right)}$
AIIMS-26.05.2018(M)
Gravitation
138248
The gravitational force with which the earth attracts the moon
1 is less than the force with which the moon attracts the earth
2 is equal to the force with which the moon attracts the earth
3 is twice than the force with which the moon attracts the earth
4 varies with the phases of moon
Explanation:
B Gravitational force between two objects of masses $m_{1}$ and $m_{2}$ separated by distance $r$ is given by $\mathrm{F}_{\mathrm{g}}=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}}$ This force is same for both the objects. If earth attracts moon with a Force F, then moon also attracts the earth with the same Force F.
J and K CET- 2002
Gravitation
138251
If the earth were to rotate faster than its present speed, the weight of an object will
1 Increase at the equator but remain unchanged at the poles
2 Decrease at the equator but remain unchanged at the poles
3 Decrease at the poles but remain unchanged at the equator
4 Increase at the pole but remain unchanged at the equator
Explanation:
B Centrifugal force is maximum at equator and minimum at pole. If the earth rotate faster than the present speed, the centrifugal force at the equator will increases. Hence, the weight of the body increase. While pole lies at the axis of rotation of earth hence the centrifugal force is zero. So, acceleration due to gravity will remains same at the pole and decreases at the equator. Therefore weight of an object decreases at the equator but remain unchanged at the pole.
JCECE-2013
Gravitation
138254
Which of the following forces have the infinite range?
1 Gravitational Force, Nuclear Force and Electromagnetic Force
2 Gravitational Force and Nuclear Force Only
3 Nuclear Force and Electromagnetic Force Only
4 Electromagnetic Force and Gravitational Force Only
Explanation:
D The range of gravitational force and electromagnetic forces are till infinite. We know that, Gravitational force $\left(\mathrm{F}_{\mathrm{g}}\right)=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{g}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$ Electrostatic force $\left(\mathrm{F}_{\mathrm{e}}\right)=\frac{\mathrm{Kq}_{1} \mathrm{q}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{e}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$
138236
Three particles each of mass $m$ are kept at vertices of an equilateral triangle of side $L$. The gravitational field at centre due to these particles is
A In equilateral triangle all sides are equal i.e. $\mathrm{AB}=\mathrm{BC}=$ $\mathrm{CA}$ and the line joining the centre of gravity to each vertex of the triangle are each at angle $120^{\circ}$ and gravitational field by each mass will be along these lines joining the centre and vertex. As triangle is equilateral, then the gravitational field produced by each mass will be same. Gravitational field produced is equal in magnitude and at an angle $120^{\circ}$. So, net field will be zero.
Manipal UGET-2010
Gravitation
138244
A satellite orbiting around the certain planet has apogee $R_{1}$ and perigee equal to $R_{2}$, then find the minimum kinetic energy that should be given to the satellite to enable it to escape from the planet.
C $\stackrel{\mathrm{R}_{1} \rightarrow}{*} \leftarrow \mathrm{R}_{2} \rightarrow$ $\mathrm{r}=\mathrm{R}_{1}+\mathrm{R}_{2}$ $\because \quad$ T. E. $=\frac{-\mathrm{GMm}}{2 \mathrm{r}}$ K. $\mathrm{E}=\mid$ T. E. $|=|-\frac{\mathrm{GMm}}{2 \mathrm{r}} \mid=\frac{\mathrm{GMm}}{2\left(\mathrm{R}_{1}+\mathrm{R}_{2}\right)}$
AIIMS-26.05.2018(M)
Gravitation
138248
The gravitational force with which the earth attracts the moon
1 is less than the force with which the moon attracts the earth
2 is equal to the force with which the moon attracts the earth
3 is twice than the force with which the moon attracts the earth
4 varies with the phases of moon
Explanation:
B Gravitational force between two objects of masses $m_{1}$ and $m_{2}$ separated by distance $r$ is given by $\mathrm{F}_{\mathrm{g}}=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}}$ This force is same for both the objects. If earth attracts moon with a Force F, then moon also attracts the earth with the same Force F.
J and K CET- 2002
Gravitation
138251
If the earth were to rotate faster than its present speed, the weight of an object will
1 Increase at the equator but remain unchanged at the poles
2 Decrease at the equator but remain unchanged at the poles
3 Decrease at the poles but remain unchanged at the equator
4 Increase at the pole but remain unchanged at the equator
Explanation:
B Centrifugal force is maximum at equator and minimum at pole. If the earth rotate faster than the present speed, the centrifugal force at the equator will increases. Hence, the weight of the body increase. While pole lies at the axis of rotation of earth hence the centrifugal force is zero. So, acceleration due to gravity will remains same at the pole and decreases at the equator. Therefore weight of an object decreases at the equator but remain unchanged at the pole.
JCECE-2013
Gravitation
138254
Which of the following forces have the infinite range?
1 Gravitational Force, Nuclear Force and Electromagnetic Force
2 Gravitational Force and Nuclear Force Only
3 Nuclear Force and Electromagnetic Force Only
4 Electromagnetic Force and Gravitational Force Only
Explanation:
D The range of gravitational force and electromagnetic forces are till infinite. We know that, Gravitational force $\left(\mathrm{F}_{\mathrm{g}}\right)=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{g}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$ Electrostatic force $\left(\mathrm{F}_{\mathrm{e}}\right)=\frac{\mathrm{Kq}_{1} \mathrm{q}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{e}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$
NEET Test Series from KOTA - 10 Papers In MS WORD
WhatsApp Here
Gravitation
138236
Three particles each of mass $m$ are kept at vertices of an equilateral triangle of side $L$. The gravitational field at centre due to these particles is
A In equilateral triangle all sides are equal i.e. $\mathrm{AB}=\mathrm{BC}=$ $\mathrm{CA}$ and the line joining the centre of gravity to each vertex of the triangle are each at angle $120^{\circ}$ and gravitational field by each mass will be along these lines joining the centre and vertex. As triangle is equilateral, then the gravitational field produced by each mass will be same. Gravitational field produced is equal in magnitude and at an angle $120^{\circ}$. So, net field will be zero.
Manipal UGET-2010
Gravitation
138244
A satellite orbiting around the certain planet has apogee $R_{1}$ and perigee equal to $R_{2}$, then find the minimum kinetic energy that should be given to the satellite to enable it to escape from the planet.
C $\stackrel{\mathrm{R}_{1} \rightarrow}{*} \leftarrow \mathrm{R}_{2} \rightarrow$ $\mathrm{r}=\mathrm{R}_{1}+\mathrm{R}_{2}$ $\because \quad$ T. E. $=\frac{-\mathrm{GMm}}{2 \mathrm{r}}$ K. $\mathrm{E}=\mid$ T. E. $|=|-\frac{\mathrm{GMm}}{2 \mathrm{r}} \mid=\frac{\mathrm{GMm}}{2\left(\mathrm{R}_{1}+\mathrm{R}_{2}\right)}$
AIIMS-26.05.2018(M)
Gravitation
138248
The gravitational force with which the earth attracts the moon
1 is less than the force with which the moon attracts the earth
2 is equal to the force with which the moon attracts the earth
3 is twice than the force with which the moon attracts the earth
4 varies with the phases of moon
Explanation:
B Gravitational force between two objects of masses $m_{1}$ and $m_{2}$ separated by distance $r$ is given by $\mathrm{F}_{\mathrm{g}}=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}}$ This force is same for both the objects. If earth attracts moon with a Force F, then moon also attracts the earth with the same Force F.
J and K CET- 2002
Gravitation
138251
If the earth were to rotate faster than its present speed, the weight of an object will
1 Increase at the equator but remain unchanged at the poles
2 Decrease at the equator but remain unchanged at the poles
3 Decrease at the poles but remain unchanged at the equator
4 Increase at the pole but remain unchanged at the equator
Explanation:
B Centrifugal force is maximum at equator and minimum at pole. If the earth rotate faster than the present speed, the centrifugal force at the equator will increases. Hence, the weight of the body increase. While pole lies at the axis of rotation of earth hence the centrifugal force is zero. So, acceleration due to gravity will remains same at the pole and decreases at the equator. Therefore weight of an object decreases at the equator but remain unchanged at the pole.
JCECE-2013
Gravitation
138254
Which of the following forces have the infinite range?
1 Gravitational Force, Nuclear Force and Electromagnetic Force
2 Gravitational Force and Nuclear Force Only
3 Nuclear Force and Electromagnetic Force Only
4 Electromagnetic Force and Gravitational Force Only
Explanation:
D The range of gravitational force and electromagnetic forces are till infinite. We know that, Gravitational force $\left(\mathrm{F}_{\mathrm{g}}\right)=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{g}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$ Electrostatic force $\left(\mathrm{F}_{\mathrm{e}}\right)=\frac{\mathrm{Kq}_{1} \mathrm{q}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{e}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$
138236
Three particles each of mass $m$ are kept at vertices of an equilateral triangle of side $L$. The gravitational field at centre due to these particles is
A In equilateral triangle all sides are equal i.e. $\mathrm{AB}=\mathrm{BC}=$ $\mathrm{CA}$ and the line joining the centre of gravity to each vertex of the triangle are each at angle $120^{\circ}$ and gravitational field by each mass will be along these lines joining the centre and vertex. As triangle is equilateral, then the gravitational field produced by each mass will be same. Gravitational field produced is equal in magnitude and at an angle $120^{\circ}$. So, net field will be zero.
Manipal UGET-2010
Gravitation
138244
A satellite orbiting around the certain planet has apogee $R_{1}$ and perigee equal to $R_{2}$, then find the minimum kinetic energy that should be given to the satellite to enable it to escape from the planet.
C $\stackrel{\mathrm{R}_{1} \rightarrow}{*} \leftarrow \mathrm{R}_{2} \rightarrow$ $\mathrm{r}=\mathrm{R}_{1}+\mathrm{R}_{2}$ $\because \quad$ T. E. $=\frac{-\mathrm{GMm}}{2 \mathrm{r}}$ K. $\mathrm{E}=\mid$ T. E. $|=|-\frac{\mathrm{GMm}}{2 \mathrm{r}} \mid=\frac{\mathrm{GMm}}{2\left(\mathrm{R}_{1}+\mathrm{R}_{2}\right)}$
AIIMS-26.05.2018(M)
Gravitation
138248
The gravitational force with which the earth attracts the moon
1 is less than the force with which the moon attracts the earth
2 is equal to the force with which the moon attracts the earth
3 is twice than the force with which the moon attracts the earth
4 varies with the phases of moon
Explanation:
B Gravitational force between two objects of masses $m_{1}$ and $m_{2}$ separated by distance $r$ is given by $\mathrm{F}_{\mathrm{g}}=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}}$ This force is same for both the objects. If earth attracts moon with a Force F, then moon also attracts the earth with the same Force F.
J and K CET- 2002
Gravitation
138251
If the earth were to rotate faster than its present speed, the weight of an object will
1 Increase at the equator but remain unchanged at the poles
2 Decrease at the equator but remain unchanged at the poles
3 Decrease at the poles but remain unchanged at the equator
4 Increase at the pole but remain unchanged at the equator
Explanation:
B Centrifugal force is maximum at equator and minimum at pole. If the earth rotate faster than the present speed, the centrifugal force at the equator will increases. Hence, the weight of the body increase. While pole lies at the axis of rotation of earth hence the centrifugal force is zero. So, acceleration due to gravity will remains same at the pole and decreases at the equator. Therefore weight of an object decreases at the equator but remain unchanged at the pole.
JCECE-2013
Gravitation
138254
Which of the following forces have the infinite range?
1 Gravitational Force, Nuclear Force and Electromagnetic Force
2 Gravitational Force and Nuclear Force Only
3 Nuclear Force and Electromagnetic Force Only
4 Electromagnetic Force and Gravitational Force Only
Explanation:
D The range of gravitational force and electromagnetic forces are till infinite. We know that, Gravitational force $\left(\mathrm{F}_{\mathrm{g}}\right)=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{g}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$ Electrostatic force $\left(\mathrm{F}_{\mathrm{e}}\right)=\frac{\mathrm{Kq}_{1} \mathrm{q}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{e}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$
138236
Three particles each of mass $m$ are kept at vertices of an equilateral triangle of side $L$. The gravitational field at centre due to these particles is
A In equilateral triangle all sides are equal i.e. $\mathrm{AB}=\mathrm{BC}=$ $\mathrm{CA}$ and the line joining the centre of gravity to each vertex of the triangle are each at angle $120^{\circ}$ and gravitational field by each mass will be along these lines joining the centre and vertex. As triangle is equilateral, then the gravitational field produced by each mass will be same. Gravitational field produced is equal in magnitude and at an angle $120^{\circ}$. So, net field will be zero.
Manipal UGET-2010
Gravitation
138244
A satellite orbiting around the certain planet has apogee $R_{1}$ and perigee equal to $R_{2}$, then find the minimum kinetic energy that should be given to the satellite to enable it to escape from the planet.
C $\stackrel{\mathrm{R}_{1} \rightarrow}{*} \leftarrow \mathrm{R}_{2} \rightarrow$ $\mathrm{r}=\mathrm{R}_{1}+\mathrm{R}_{2}$ $\because \quad$ T. E. $=\frac{-\mathrm{GMm}}{2 \mathrm{r}}$ K. $\mathrm{E}=\mid$ T. E. $|=|-\frac{\mathrm{GMm}}{2 \mathrm{r}} \mid=\frac{\mathrm{GMm}}{2\left(\mathrm{R}_{1}+\mathrm{R}_{2}\right)}$
AIIMS-26.05.2018(M)
Gravitation
138248
The gravitational force with which the earth attracts the moon
1 is less than the force with which the moon attracts the earth
2 is equal to the force with which the moon attracts the earth
3 is twice than the force with which the moon attracts the earth
4 varies with the phases of moon
Explanation:
B Gravitational force between two objects of masses $m_{1}$ and $m_{2}$ separated by distance $r$ is given by $\mathrm{F}_{\mathrm{g}}=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}}$ This force is same for both the objects. If earth attracts moon with a Force F, then moon also attracts the earth with the same Force F.
J and K CET- 2002
Gravitation
138251
If the earth were to rotate faster than its present speed, the weight of an object will
1 Increase at the equator but remain unchanged at the poles
2 Decrease at the equator but remain unchanged at the poles
3 Decrease at the poles but remain unchanged at the equator
4 Increase at the pole but remain unchanged at the equator
Explanation:
B Centrifugal force is maximum at equator and minimum at pole. If the earth rotate faster than the present speed, the centrifugal force at the equator will increases. Hence, the weight of the body increase. While pole lies at the axis of rotation of earth hence the centrifugal force is zero. So, acceleration due to gravity will remains same at the pole and decreases at the equator. Therefore weight of an object decreases at the equator but remain unchanged at the pole.
JCECE-2013
Gravitation
138254
Which of the following forces have the infinite range?
1 Gravitational Force, Nuclear Force and Electromagnetic Force
2 Gravitational Force and Nuclear Force Only
3 Nuclear Force and Electromagnetic Force Only
4 Electromagnetic Force and Gravitational Force Only
Explanation:
D The range of gravitational force and electromagnetic forces are till infinite. We know that, Gravitational force $\left(\mathrm{F}_{\mathrm{g}}\right)=\frac{\mathrm{Gm}_{1} \mathrm{~m}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{g}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$ Electrostatic force $\left(\mathrm{F}_{\mathrm{e}}\right)=\frac{\mathrm{Kq}_{1} \mathrm{q}_{2}}{\mathrm{r}^{2}} \quad \mathrm{~F}_{\mathrm{e}} \rightarrow 0$ if $\mathrm{r} \rightarrow \infty$
