368901
Assertion : Propagation of electromagnetic waves (of \(2\,MHz\) to \(30\,MHz\)) is done by Sky wave method. Reason : These waves are reflected back to earth by ionosphere.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Ionosphere her its refrective index \((n)\) given by \(n=n_{o}\left[\dfrac{1-(80.5 \mathrm{Ne})}{f^{2}}\right]^{1 / 2}\) where \(n_{0}=\) that of free space. here, \(N_{e}\) is electron - density which increases as these waves be deep into ionosphere. So correct option is (1).
PHXII08:ELECTROMAGNETIC WAVES
368902
Statement A : One should not use metal containers in a microwave oven. Statement B : Only because metal may melt from heating.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
When microwaves hit metal objects, they get reflected. This continuous reflection causes a fire. So optoin (3) is correct.
PHXII08:ELECTROMAGNETIC WAVES
368903
Assertion : The television broadcasting becomes weaker with increasing distance. Reason : The power transmitted from \(T V\) transmitter varies inversely as the distance of the receiver
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Power \(\propto \dfrac{1}{r^{2}}\left(\operatorname{not} \dfrac{1}{r}\right)\) \(T V\) signals weaken with distance following the inverse square law, diminishing in strength. As they spread over a larger area. additional transmitters or repeaters will be needed to extend coverage. So correct option is (3).
PHXII08:ELECTROMAGNETIC WAVES
368904
An antenna of length \(25\;m\) is mounted on top of a building of height \(75\;m\). Then the maximum wavelength of the transmission signal is close to :
368901
Assertion : Propagation of electromagnetic waves (of \(2\,MHz\) to \(30\,MHz\)) is done by Sky wave method. Reason : These waves are reflected back to earth by ionosphere.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Ionosphere her its refrective index \((n)\) given by \(n=n_{o}\left[\dfrac{1-(80.5 \mathrm{Ne})}{f^{2}}\right]^{1 / 2}\) where \(n_{0}=\) that of free space. here, \(N_{e}\) is electron - density which increases as these waves be deep into ionosphere. So correct option is (1).
PHXII08:ELECTROMAGNETIC WAVES
368902
Statement A : One should not use metal containers in a microwave oven. Statement B : Only because metal may melt from heating.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
When microwaves hit metal objects, they get reflected. This continuous reflection causes a fire. So optoin (3) is correct.
PHXII08:ELECTROMAGNETIC WAVES
368903
Assertion : The television broadcasting becomes weaker with increasing distance. Reason : The power transmitted from \(T V\) transmitter varies inversely as the distance of the receiver
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Power \(\propto \dfrac{1}{r^{2}}\left(\operatorname{not} \dfrac{1}{r}\right)\) \(T V\) signals weaken with distance following the inverse square law, diminishing in strength. As they spread over a larger area. additional transmitters or repeaters will be needed to extend coverage. So correct option is (3).
PHXII08:ELECTROMAGNETIC WAVES
368904
An antenna of length \(25\;m\) is mounted on top of a building of height \(75\;m\). Then the maximum wavelength of the transmission signal is close to :
368901
Assertion : Propagation of electromagnetic waves (of \(2\,MHz\) to \(30\,MHz\)) is done by Sky wave method. Reason : These waves are reflected back to earth by ionosphere.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Ionosphere her its refrective index \((n)\) given by \(n=n_{o}\left[\dfrac{1-(80.5 \mathrm{Ne})}{f^{2}}\right]^{1 / 2}\) where \(n_{0}=\) that of free space. here, \(N_{e}\) is electron - density which increases as these waves be deep into ionosphere. So correct option is (1).
PHXII08:ELECTROMAGNETIC WAVES
368902
Statement A : One should not use metal containers in a microwave oven. Statement B : Only because metal may melt from heating.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
When microwaves hit metal objects, they get reflected. This continuous reflection causes a fire. So optoin (3) is correct.
PHXII08:ELECTROMAGNETIC WAVES
368903
Assertion : The television broadcasting becomes weaker with increasing distance. Reason : The power transmitted from \(T V\) transmitter varies inversely as the distance of the receiver
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Power \(\propto \dfrac{1}{r^{2}}\left(\operatorname{not} \dfrac{1}{r}\right)\) \(T V\) signals weaken with distance following the inverse square law, diminishing in strength. As they spread over a larger area. additional transmitters or repeaters will be needed to extend coverage. So correct option is (3).
PHXII08:ELECTROMAGNETIC WAVES
368904
An antenna of length \(25\;m\) is mounted on top of a building of height \(75\;m\). Then the maximum wavelength of the transmission signal is close to :
368901
Assertion : Propagation of electromagnetic waves (of \(2\,MHz\) to \(30\,MHz\)) is done by Sky wave method. Reason : These waves are reflected back to earth by ionosphere.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Ionosphere her its refrective index \((n)\) given by \(n=n_{o}\left[\dfrac{1-(80.5 \mathrm{Ne})}{f^{2}}\right]^{1 / 2}\) where \(n_{0}=\) that of free space. here, \(N_{e}\) is electron - density which increases as these waves be deep into ionosphere. So correct option is (1).
PHXII08:ELECTROMAGNETIC WAVES
368902
Statement A : One should not use metal containers in a microwave oven. Statement B : Only because metal may melt from heating.
1 Statement A is correct but Statement B is incorrect.
2 Statement A is incorrect but Statement B is correct.
3 Both statements are correct.
4 Both Statements are incorrect.
Explanation:
When microwaves hit metal objects, they get reflected. This continuous reflection causes a fire. So optoin (3) is correct.
PHXII08:ELECTROMAGNETIC WAVES
368903
Assertion : The television broadcasting becomes weaker with increasing distance. Reason : The power transmitted from \(T V\) transmitter varies inversely as the distance of the receiver
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Power \(\propto \dfrac{1}{r^{2}}\left(\operatorname{not} \dfrac{1}{r}\right)\) \(T V\) signals weaken with distance following the inverse square law, diminishing in strength. As they spread over a larger area. additional transmitters or repeaters will be needed to extend coverage. So correct option is (3).
PHXII08:ELECTROMAGNETIC WAVES
368904
An antenna of length \(25\;m\) is mounted on top of a building of height \(75\;m\). Then the maximum wavelength of the transmission signal is close to :
