Verify self-signed TLS certificate for HTTPS in Ruby

How to use SSL certificate verification (using password parameter in URL) in RUBY's GET Request? ->

require 'net/https'
require 'uri'

uri = URI.parse(ARGV[0] || 'https://example.com?password=my_password')

http = Net::HTTP.new(uri.host, uri.port)

if uri.scheme == "https" 

    http.use_ssl = true
    http.verify_mode = OpenSSL::SSL::VERIFY_PEER
    http.ca_file=File.join(File.dirname(__FILE__),
             "/Users/me/Desktop/demp.pem")
end

http.start do
    http.request_get(uri.path) do |res|

print res.body

end

end

-> output

SSL_connect return=1 errno=0 status=error: certificate verification failed (self-signed certificate in certificate chain) (OpenSSL::SSL::SSLError)