Answer:
a. 0.8 cm
Explanation:
The distance of the object from the lens, u = 1 cm
The magnification of the lens, m = 5
The focus of a lens formula is given as follows;

The magnification of the lens, m = -v/u
Where;
v = The distance of the image from the lens
Therefore, we have;
v = m × u
∴ v = 5 × 1 cm = 5 cm (on the other side of the lens)
From which we get;

The focal length ≈ 0.8 cm
Answer:
The charge carried by the droplet is 
Explanation:
Given that,
Distance =8.4 cm
Time = 0.250 s
Suppose tiny droplets of oil acquire a small negative charge while dropping through a vacuum in an experiment. An electric field of magnitude
points straight down and if the mass of the droplet is 
We need to calculate the acceleration
Using equation of motion

Put the value into the formula



We need to calculate the charge carried by the droplet
Using formula of electric filed


Put the value into the formula


Hence, The charge carried by the droplet is 
Mechanical advantage (MA = slope/height)
here length of slope = 9Hheight = H so mechanical advantage = ---- 9H/H= 9
Answer:
Induced emf will be 0.468 volt
Explanation:
We have given diameter of wire d = 15.3 cm
So radius 
So area 
Change in magnetic field dB = 0.26 - 0.77 = -0.51 T
Time for change in magnetic field dt = 0.26 sec
We know that emf is given by 