V30-19

Question

In the early 19th century, two developments in the field of electricity opened the door to the production of the electric telegraph. First, in 1800, the Italian physicist Alessandro Volta invented the battery, which reliably stored an electric current and allowed the current to be used in a controlled environment. Second, in 1820, the Danish physicist Hans Christian Oersted demonstrated the connection between electricity and magnetism by deflecting a magnetic needle with an electric current. While scientists and inventors across the world began experimenting with batteries and the principles of electromagnetism to develop some kind of communication system, the credit for inventing the telegraph generally falls to two sets of researchers: Sir William Cooke and Sir Charles Wheatstone in England, and Samuel Morse, Leonard Gale and Alfred Vail in the U.S.
 
In the 1830s, the British team of Cooke and Wheatstone developed a telegraph system with five magnetic needles that could be pointed around a panel of letters and numbers by using an electric current. Their system was soon being used for railroad signaling in Britain. During this period, the Massachusetts-born, Yale-educated Morse (who began his career as a painter), worked to develop an electric telegraph of his own. He reportedly had become intrigued with the idea after hearing a conversation about electromagnetism while sailing from Europe to America in the early 1830s and later learned more about the topic from American physicist Joseph Henry. In collaboration with Gale and Vail, Morse eventually produced a single-circuit telegraph that worked by pushing the operator key down to complete the electric circuit of the battery. This action sent the electric signal across a wire to a receiver at the other end. All the system needed was a key, a battery, wire and a line of poles between stations for the wire and a receiver.

All of the following are cited in the passage as contributing to the invention of the electric telegraph EXCEPT

A. the invention of the battery in the 19th century that reliably stored electric current.
B. the 5-needle telegraph system that used electromagnetism to point needles around a panel of letters and numbers.
C. the development of Morse code that facilitated a universal and binary communication system.
D. the instruction Samuel Morse received from American physicist Joseph Henry, which deepened his understanding of electromagnetism.
E. the contribution of Danish physicist Hans Christian Oersted in the field of electromagnetism to demonstrate mechanical movements of magnets placed in an electric current.

souvik101990 · Answer

Official Solution:

In the early 19th century, two developments in the field of electricity opened the door to the production of the electric telegraph. First, in 1800, the Italian physicist Alessandro Volta invented the battery, which reliably stored an electric current and allowed the current to be used in a controlled environment. Second, in 1820, the Danish physicist Hans Christian Oersted demonstrated the connection between electricity and magnetism by deflecting a magnetic needle with an electric current. While scientists and inventors across the world began experimenting with batteries and the principles of electromagnetism to develop some kind of communication system, the credit for inventing the telegraph generally falls to two sets of researchers: Sir William Cooke and Sir Charles Wheatstone in England, and Samuel Morse, Leonard Gale and Alfred Vail in the U.S.
 
In the 1830s, the British team of Cooke and Wheatstone developed a telegraph system with five magnetic needles that could be pointed around a panel of letters and numbers by using an electric current. Their system was soon being used for railroad signaling in Britain. During this period, the Massachusetts-born, Yale-educated Morse (who began his career as a painter), worked to develop an electric telegraph of his own. He reportedly had become intrigued with the idea after hearing a conversation about electromagnetism while sailing from Europe to America in the early 1830s and later learned more about the topic from American physicist Joseph Henry. In collaboration with Gale and Vail, Morse eventually produced a single-circuit telegraph that worked by pushing the operator key down to complete the electric circuit of the battery. This action sent the electric signal across a wire to a receiver at the other end. All the system needed was a key, a battery, wire and a line of poles between stations for the wire and a receiver.
 
 All of the following are cited in the passage as contributing to the invention of the electric telegraph EXCEPT

A. the invention of the battery in the 19th century that reliably stored electric current.
B. the 5-needle telegraph system that used electromagnetism to point needles around a panel of letters and numbers.
C. the development of Morse code that facilitated a universal and binary communication system.
D. the instruction Samuel Morse received from American physicist Joseph Henry, which deepened his understanding of electromagnetism.
E. the contribution of Danish physicist Hans Christian Oersted in the field of electromagnetism to demonstrate mechanical movements of magnets placed in an electric current.

A) This option is mentioned in the opening sentence: “In 1800, the Italian physicist Alessandro Volta invented the battery, which reliably stored an electric current and allowed the current to be used in a controlled environment.” The battery provided the stable power source every later design relied on.
 
B) This contribution is mentioned in Paragraph 2: Cooke & Wheatstone “developed a telegraph system with five magnetic needles that could be pointed around a panel of letters and numbers by using an electric current.” This British prototype proved the basic signaling concept.
 
C) Correct Answer. Nowhere does the passage mention Morse code. The text limits Morse’s contribution to the hardware, a single-circuit key-and-receiver telegraph. 
 
D) This contribution is found in Paragraph 2: Morse “later learned more about the topic from American physicist Joseph Henry.” Henry’s guidance helped Morse refine his design; thus it aided the invention effort. 
 
E) This contribution is found in the first paragraph: Oersted “demonstrated the connection between electricity and magnetism by deflecting a magnetic needle with an electric current.” His discovery supplied the key scientific principle underlying telegraph signaling.

Answer: C

Fifina · Answer

souvik101990 , according to the explanation you provided, answer choice D also seems to be out of scope. Can you point me to a fragment in the text that mentions "Worldwide experimentation with batteries"?

pshamshery · Answer

'While scientists and inventors across the world began experimenting with batteries and the principles of electromagnetism to develop some kind of communication system, the credit for inventing the telegraph generally falls to two sets of researchers: Sir William Cooke and Sir Charles Wheatstone in England, and Samuel Morse, Leonard Gale and Alfred Vail in the U.S.'

Anirudh134 · Answer

The invention of electromagnetism was done in 1800 but option A says ut was done in 19 and that i feel is out of scope ! Can anyone please explain where i am wrong?

jainbob · Answer

I don't understand how Option B i.e. Cooke and Wheatstone telegraph system helped in the invention of Electric Telegraph (i.e. the one made in US). It is nowhere mentioned in the passage.

saby1410 · Answer

I think this is a  poor-quality  question and the explanation isn't clear enough, please elaborate.

shreyata · Answer

A) the paragraph states this: "In the early 19th century, two developments in the field of electricity opened the door to the production of the electric telegraph. First, in 1800, the Italian physicist Alessandro Volta invented the battery, which reliably stored an electric current and allowed the current to be used in a controlled environment." Eliminate A
B) The paragraph mentions that "In the 1830s, the British team of Cooke and Wheatstone developed a telegraph system with five magnetic needles that could be pointed around a panel of letters and numbers by using an electric current." Eliminate B
D) "While scientists and inventors across the world began experimenting with batteries and the principles of electromagnetism to develop some kind of communication system" Eliminate D
E) " Second, in 1820, the Danish physicist Hans Christian Oersted demonstrated the connection between electricity and magnetism by deflecting a magnetic needle with an electric current." Eliminate E

We are left with C. so C is the answer

henryegan · Answer

I don’t quite agree with the solution. While I agree that C is correct - the battery sentence said nothing about storing electric current, only producing. This is a poor question imo.

bb · Answer

Thank you for the comment. Which sentence are you referring to?

I see this one:

First, in 1800, the Italian physicist Alessandro Volta invented the  battery, which reliably stored an electric current  and allowed the current to be used in a controlled environment.

I have gone ahead and updated the explanation for incorrect options as well since it was focusing only on the correct answer.

ritzysharma · Answer

The passage does not mention any Joseph Henry, then how can we eliminate option D?

preciouslyanxious · Answer

Yes Exactly. I was wondering the same. Plus also where is the word 5 needle mentioned in the passage?

hr1212 · Answer

I think this question could use a bit of rework. To me, both C and D looked like valid answers, and I ended up guessing between them since I couldn’t confidently rule one out. The official explanation also seems to reference a line that isn’t in the original passage, so there may be some mix-up there.

bb - Could we please take another look at this?

bb  - Could we please take another look at this?

oditaliquid · Answer

The correct answer is C. the development of Morse code that facilitated a universal and binary communication system.

oditaliquid · Answer

Here’s why:

The passage mentions Alessandro Volta’s battery (A) as enabling systematic experiments with electricity. ✅

It describes the multiple-needle telegraph by Cooke and Wheatstone (B). ✅

It cites Hans Christian Oersted’s work in electromagnetism (E). ✅

It mentions Samuel Morse’s learning and experiments with electromagnetism (D), though Joseph Henry isn’t explicitly named, the concept of instruction isn’t included in the passage, but it’s closer than C.

bb · Answer

Thank you hr1212 . Morse code is not mentioned in the passage. Mr. Morse is mentioned as helping contribute to the hardware project but nothing is said about the code... does that make it less valid of an answer? or is this too dirty of a trick?

hr1212 · Answer

I have no concerns with option C, even I selected it over D. But I think there aren’t concrete reasons to eliminate D, and the official explanation seems a bit off because even I couldn’t find that information in the passage -

This contribution is found in Paragraph 2: Morse “later learned more about the topic from American physicist Joseph Henry.” Henry’s guidance helped Morse refine his design; thus it aided the invention effort.

bb · Answer

Oh. Yes. I see the problem. I have updated the question Option D on Aug 19th but not the passage....

Made the change. Thank you @ ritzysharma

bb · Answer

Hi. It is the first sentence of the second paragraph.

In the 1830s, the British team of Cooke and Wheatstone developed a telegraph system with  five  magnetic needles

V30-19

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards