# Physics - Assist pls!

When a certain a.c. supply is connected to a lamp, it lights with the same brightness as it does with a 12V battery

a) what is the r.m.s. value of the a.c. supply?
b) what is the peak p.d. of the a.c. supply?

Isn't rms value the same effective value as DC? What does root mean square give you if not that?

1. 👍 0
2. 👎 0
3. 👁 89

## Similar Questions

A lamp connected to a battery lights up. If a second, identical lamp is connected to the battery in parallel, the current drawn from the battery will _____ , and compared to the original brightness of the first lamp, both lamps

asked by matthew on May 12, 2012
2. ### science

What can be concluded if the family finds out the lights in the bathroom work, but the floor lamp and tv set still do not work? 1. The electrical service to the cabin has not gone off. 2. The bathroom lights are on the same

asked by miss on May 28, 2016
3. ### Physics

Is true or false- a lamp functioning at peak voltage (AC) will glow with the same brightness when connected to a battery of the same voltage (DC)? PLZ DNT 4GT 2 XPLAIN DA ANSWER

asked by Georgina on October 10, 2010
4. ### physics 102

three lamps connected to a 120-V AC (rms) household supply voltage. Lamps 1 and 2 have 75.0-W bulbs; lamp 3 has a 40.0-W bulb. (a) For each bulb, find the rms current. Irms, lamp 1 = A Irms, lamp 2 = A Irms, lamp 3 = A (b) For

asked by Matt Will on August 9, 2012
5. ### science

A family is seated around the fireplace in a mountain cabin on a rainy night. A bright flash of lightning lights up the room and is followed in less than a second by a loud clap of thunder. The light bulb in a floor lamp flickers

asked by miss on May 28, 2016
6. ### Physics

A 100 W lamp is connected to 120 V, and its current is measured. A resistor is added to the lamp to reduce the current to half its original value. (a) What is the potential difference across the lamp? (b) How much resistance was

asked by Billy on April 14, 2013
7. ### Calculus-Math

Delta Cephei is one of the most visible stars in the night sky. Its brightness has periods of 5.4 days, the average brightness is 4.0 and its brightness varies by plus-or-minus 0.35. Find a formula that models the brightness, b,

asked by E on September 22, 2017
8. ### Physics

#1. Ten Christmas lights are connected in series and plugged into a 120 V wall outlet. Each light is identical and can be thought of as a resistor. a) What should the value of this resistance be if the total string is to dissipate

asked by Bartholomew on September 20, 2010
9. ### Physics

#1. Ten Christmas lights are connected in series and plugged into a 120 V wall outlet. Each light is identical and can be thought of as a resistor. a) What should the value of this resistance be if the total string is to dissipate

asked by Sam on September 20, 2010
10. ### Science PHYSICS

What happens to total voltage if multiple cells are connected in series? Connected in parallel? 2. What happens to the voltage, current and brightness of the bulbs if they are connected in series? connected in parralel

asked by help on June 18, 2018

More Similar Questions