Answer:
she must increase the current by factor of 7
Explanation:
The magnetic field produced by a steady current flowing in a very long straight wire encircles the wire.In order to solve the question, we use this formula,
B= μo I/(2πr)
where,
'μo' represents permeability of free space i.e 4π*10-7 N/A2
B=magnetic field
I= current
r=radius
->When r= 1cm=> 0.01m
B1 = μo 
/(2π x 0.01)
->when r=7cm =>0.07m
B2 = μo 
/(2π x 0.07)
Now equating both of the magnetic fields, we have
B1= B2
μo /(2π x 0.01)= μo /(2π x 0.07)
/ = 0.01/0.07
/ = 1/ 7
Therefore, she must increase the current by factor of 7
Answer:
Attracting means pulling toward you and repelling means pushing away
Explanation:
Answer:
I think it's 250
Explanation:
If the car is traveling 50 km/hr that means every hour, the car drives 50 km. So if you want to know how far it will go in 5 hours you do 50x5.
Answer;
B. Fluorescent lamps operate at a higher temperature than incandescent lamps.
Explanation;
-A fluorescent lamp, is a type of electric light (lamp) that uses ultraviolet emitted by mercury vapor to excite a phosphor, which emits visible light.
-A fluorescent lamp produces less heat, thus, it is much more efficient. A fluorescent bulb can produce between 50 and 100 lumens per watt. This makes fluorescent bulbs four to six times more efficient than incandescent bulbs.
-Fluorescent lamps operate best around room temperature. At much lower or higher temperatures, efficacy decreases.
