Answer: A,B, and E
Explanation: Just checked I got them right:)
So we want to know what is the distance d of the object from the lens if the height of the object is h=6 cm, focal length of the lens is f=5 cm and the distance d=15 cm is the distance of the object from the lens. From the formula for the convex lens 1/f=(1/D + 1/d) where D is the distance of the image from the lens we can get D after solving for D: 1/D=(1/f) - (1/d),
1/D=(1/5)-(1/15)=0.2-0,06667=0.13333 so f=1/0.13333=7.500187 cm. Rounded to the nearest hundredth D=7.50 cm. That is very close to 7.69 cm so the correct answer is the third one.
Answer:30.08 ms
Explanation:
Given
time Constant 
Also rate at which energy is dissipated in the resistor equal to the rate at which energy is stored in inductor's magnetic Field
Energy stored in Inductor is 
rate of Energy storing 
Rate of Energy dissipation from resistor i.e. Power is given by
Equating 1 and 2
i is given by 
substitute the value of 
in 3
This is the open switch 2 cells connecting wire and bulb
