When three identical bulbs of 60W,200V rating are connected in series at a 200V supply the power drawn by them will be?

P = 180 [w]

Explanation:

To solve this problem we must use ohm's law, which is defined by the following formula.

V = I*R & P = V*I

where:

V = voltage = 200[volts]

I = current [amp]

R = resistance [ohm]

P = power [watts]

Since the bulbs are connected in series, the powers should be summed

P = 60 + 60 + 60

P = 180 [watts]

Now we can calculate the current

I = 180/200

I = 0.9[amp]

Attached is an image where we see the three bulbs connected in series, in the circuit we see that the current is the same for all the elements connected to the circuit.

And the power is defined by P = V*I

we know that the voltage is equal to 200[V], therefore

P = 200*0.9

P = 180 [w]

wavelength divides in half and speed stays the same.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia