Answer: A and B
Explanation:
Electromagnetic radiations are examples of electromagnetic waves with increasing frequency and decreasing wavelength in the following order radiowaves - infrared waves - visible lights - ultraviolet rays- x-rays - gamma rays.
They did not require material medium for their propagation.
The statement above shows that EM radiations possesses different wavelengths and frequency.
Answer:
1/3 the distance from the fulcrum
Explanation:
On a balanced seesaw, the torques around the fulcrum calculated on one side and on another side must be equal. This means that:
where
W1 is the weight of the boy
d1 is its distance from the fulcrum
W2 is the weight of his partner
d2 is the distance of the partner from the fulcrum
In this problem, we know that the boy is three times as heavy as his partner, so
If we substitute this into the equation, we find:
and by simplifying:
which means that the boy sits at 1/3 the distance from the fulcrum.
the correct choice is
C) an electric current.
as a magnet is turned quickly relative to a coil, the magnetic flux linked with coil varies due to variation of angle of direction of magnetic field with normal to the plane of coil. the coil resist this change of magnetic flux in it by inducing emf in it so as to nullify the variation in magnetic flux. Due to this induced emf , electric current flows through the coil.
Explanation:
Since, it is given that the magnet drops and falls lengthwise towards the canter of the ring. As a result, change in magnetic flux will occur which tends to induce an electric current in the ring.
Therefore, a magnetic field is also produced by the ring itself which will actually oppose or repel the magnet.
Thus, we can conclude that the falling magnet be repelled by the ring due to the magnetic interaction of the magnet and the ring.
