R=U^2/P=120*120/40=360 ohm
P2=U2^2/R=132*132/360=48.4 w
power increase ratio (48.4-40)/40=21%
Answer: O:right
Explanation: In this case you place your finger on the current, and your fingers should curl showing the way, you must use your right hand in this case, otherwise that would mean the fingers on your left would bend way back, and snap off, (Not really lol, just saying)
Work is force times distance. If there's no distance, there's no work being done.
Answer:

Explanation:
d = Diameter of spot = 30 μm
r = Radius of spot = 
P = Power of the laser = 
A = Area = 
Intensity is given by

The light intensity within this spot is 
Answer:
a.6.5025 J
b.6.5025 J
Explanation:
We are given that
Mass of pellet,m=0.27 g=
1 kg=1000 g
Spring constant,k=1800 N/m
x=8.5 cm=
1m=100 cm
a.Potential energy stored in the compressed spring is given by
P.E=


b.By using law of conservation of energy
P.E of spring=K.E of the pellet
K.E of the pellet=6.5025 J