Answer:
A
Explanation:
Iron and gadlinium are both very easily made into magnetic substances.  Cobalt is also capable of being magnetized. Aluminum, put in an alloy, can make a magnetic substance, but
Aluminum by itself is not able to be magnetized.
 
        
             
        
        
        
Answer: 117.60N
Explanation:
Weight is a force. Therefore, we can use the force formula to find weight.

W = weight
m = mass
g = acceleration due to gravity ( )
)

 
        
                    
             
        
        
        
Answer:
Rs. 480.00
Explanation:
1kW = 1000W
therefore 500W = 0.5kW
20 × 24hrs = 480hrs in total.
0.5kW × 480hrs = 240kWh
if rs. 2 for 1kWh 
then, 240kWh × 2 = Rs. 480.
 
        
                    
             
        
        
        
Answer:
2442.5 Nm
Explanation:
Tension, T = 8.57 x 10^2 N 
length of rope, l = 8.17 m 
y = 0.524 m 
h = 2.99 m 
According to diagram 
Sin θ = (2.99 - 0.524) / 8.17 
Sin θ = 0.3018 
θ = 17.6°
So, torque about the base of the tree is 
Torque = T x Cos θ x 2.99 
Torque = 8.57 x 100 x Cos 17.6° x 2.99 
Torque = 2442.5 Nm
thus, the torque is 2442.5 Nm. 
 
        
             
        
        
        
'In transverse waves, the particles of the medium move perpendicular to the direction of the flow of energy' is true for transverse waves only.
'In longitudinal waves, the particles of the medium move parallel to the direction of the flow of energy' is true for longitudinal waves only.
'Many wave motions in nature are a combination of longitudinal and transverse motion' is true for both longitudinal and transverse waves.
<u>Explanation:</u>
Longitudinal waves are those where the direction of propagation of particles are parallel to the medium' particles. While transverse waves propagate perpendicular to the medium' particles.
As wave motions are assumed to be of standing waves which comprises of particles moving parallel as well as perpendicular to the medium, most of the wave motions are composed of longitudinal and transverse motion.
So the option stating the medium' particle moves perpendicular to the direction of the energy flow is true for transverse waves. Similarly, the option stating the medium' particle moves parallel to the direction of flow of energy is true for longitudinal waves only.
And the option stating that wave motions comprises of combination of longitudinal and transverse motion is true for both of them.