Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

A 25cm long pinhole camera produces a one-fifth of an object's size. Calculate the object...

Physics
JAMB 2025

A 25cm long pinhole camera produces a one-fifth of an object's size. Calculate the object distance 

  • A. 20.49m
  • B. 2.82m
  • C. 4.23m
  • D. 1.25m
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 - 127076
WAEC offline past questions - with all answers and explanations in one app - Download for free
Correct Answer: Option D
Explanation

D. 1.25 m

In a pinhole camera, the relationship between image size and object size is given by:
\(\frac{\text{Image Size}}{\text{Object Size}} = \frac{v}{u}\)
where \( v \) is the camera length. Given \( v = 25 \, \text{cm} = 0.25 \, \text{m} \).

The image is one-fifth the object size, so the magnification is:
\(\text{Magnification} = \frac{1}{5} = \frac{v}{u}\)
Thus, we can rearrange this to find \( u \):
\(u = 5v = 5 \times 0.25 = 1.25 \, \text{m}\).

There is an explanation video available below.


Report an Error Ask A Question Download App
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 127076
Post UTME Past Questions Agent
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

Explanation Video

WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Post UTME Past Questions Agent

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 - 127076
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC offline past questions - with all answers and explanations in one app - Download for free
Post UTME Past Questions Agent
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC offline past questions - with all answers and explanations in one app - Download for free
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC Past Questions, Objective & Theory, Study 100% offline, Download app now - 127076
Post UTME Past Questions Agent