WAEC offline past questions - with all answers and explanations in one app - Download for free
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

The effect of closing the key K in the circuit shown in the figure above...

Physics
JAMB 2020

The effect of closing the key K in the circuit shown in the figure above would be to?

  • A. increase the current by 0.4A
  • B. reduce the current by 0.4A
  • C. increase the current by 0.6A
  • D. reduce the current by 0.6A
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
Correct Answer: Option A
Explanation

When K is open. Total Resistance = 8 + 2 = 10\(\Omega\)

1 = \(\frac{V}{\Omega}\) =  \(\frac{6v}{\Omega}\) = 0.6A

Where K is closed, \(\frac{1}{8} + \frac{1}{8} = \frac{1}{\Omega}\) 

\(\frac{2}{8} = \frac{1}{\Omega}\)

\(\Omega\) = \(\frac{8}{2}\) = 4\(\Omega\)

\(\Omega\) = \(\frac{8}{2}\) = 4\(\Omega\)

4\(\Omega\)  in series with 2\(\Omega\)= 6\(\Omega\)

1 = \(\frac{V}{\Omega}\)  = \(\frac{6}{6}\) = 1A

1 - 0.6A = 0.4A increase

There is an explanation video available below.


Report an Error Ask A Question Download App
WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

Explanation Video

Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 24709
WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC May/June 2024 - Practice for Objective & Theory - From 1988 till date, download app now - 99995
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts