The emf of a battery is equal to its terminal potential difference:
A) under all conditions
B) only when the battery is being charged
C) only when a large current is in the battery
D) only when there is no curent in the battery
E) under no conditions

my answer: d, The chemical potential energy of real battery decreases, it develops internal resistance and therefore the potential difference across its terminals decreases if its current increases.

Four wires meet at a junction. The first carries 4A into the junction and the second carries 5 A out of the junction, and the third carries 2A out of the junction. The fourth carries:
A) 7 A out of the junction
B) 7 A into the junction
c) 3A out of the junction
d) 3 A into the junction
e) 1 A into the junction

My answer: D, conservation of charge
so 7 A out of the junction
4 A in the junction. So three A in the junction to balance the charge.

Thank you

I agree with both of your answers.

  1. 👍 0
  2. 👎 0
  3. 👁 142
asked by susane

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    Please can you help out: 1)The Potential diff across the terminals of a battery is 8.5v when there is a current of 3amps in the cct from the -ve to the +ve terminal. When the current is 2amps in the reverse direction, the

    asked by Charles on April 17, 2007
  2. Physics

    When a battery is not used in a circuit, a voltmeter measure 1.492V across the terminals of the battery. When a 2.50Ω light bulb is connected to the battery, the potential difference across the terminal of the battery is 1.453V.

    asked by exo-L on December 13, 2018
  3. physics (please check)

    Four 20-ohm resistors are connected in series and the combination is connected to a 20 V emf device. The current in any one of the resistors is: A) .25 A B) 1.0 A c) 4.0 A D) 5.0 A E) 100 A My answer: A R= 20 + 20 + 20 + 20 =80 V=

    asked by susane on March 28, 2007

    An automobile battery has an emf of 12.6 V and an internal resistance of 0.0500 . The headlights together present equivalent resistance 5.60 (assumed constant). (a) What is the potential difference across the headlight bulbs when

    asked by priya on September 6, 2013
  5. Physics

    The terminal voltage of a battery is 5.0V when 0.55A current is drawn from it, whereas the terminal voltage is 5.7V when a current of 0.180A is drawn. The emf of the battery is? The formula I used was V_(ab) = Emf - I*r First

    asked by Amid on July 3, 2016
  6. Physics

    A battery with an emf of 10.3 V and internal resistance of 1.03 Ω carries a positive current of 0.550 A from its negative terminal to its positive terminal. (a) How long is required for 1.05 C of charge to pass through the

    asked by Brandi on July 7, 2014
  7. physics

    i am confused with the concept when electrons flow from the negative terminal to the positive terminal of a battery then why the negative one is called lower potential and positive one higher potential while the difference in

    asked by help(in much need)!!!!!!!!!!!!!!!!!!!! on September 26, 2013
  8. Physics

    A battery has an unknown e.m.f, ε,and an internal resistance r = 0.40Ω. When a resistance R = 5.60Ω is connected across the terminals of the battery, the terminal potential difference across the battery is 11.2V. What is the

    asked by prada on December 13, 2018
  9. physical

    A battery of e.m.f 24v and internal resistance of 4ohms is connected to a resistor of 3ohms.what is the terminal potential difference of the battery

    asked by vincent on March 6, 2011
  10. Physics

    A battery has an emf of 15.0 V. The terminal voltage of the battery is 11.2 V when it is delivering 26.0 W of power to an external load resistor R. (a) What is the value of R? (b) What is the internal resistance of the battery?

    asked by Jasmine on February 16, 2015

More Similar Questions