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Multiple choice physics chemical effects of electric current study about cells electric cell types of cells

Five cells each of emf $\varepsilon $ and internal resistance r each are connected in series. If one cell is connected wrongly, then potential difference across this cell will be

  1. $\dfrac { 8\varepsilon }{ 5 } $

  2. zero
  3. $\dfrac { 4\varepsilon }{ 5 } $
  4. $\dfrac { 2\varepsilon }{ 5 } $
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When five cells of emf epsilon and internal resistance r are in series, the total emf is 5 epsilon and total internal resistance is 5r. If one cell is connected with reverse polarity, the net emf becomes 5 epsilon - 2 epsilon = 3 epsilon, and the current in the circuit is I = (3 epsilon) / (5r). The potential difference across the wrongly connected cell is V = epsilon_cell + I*r = epsilon + ((3 epsilon)/(5r))*r = epsilon + (3/5)epsilon = (8 epsilon) / 5.

Multiple choice physics chemical effects of electric current study about cells electric cell types of cells

A wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by $\Delta\ T$ in a time $t$. A number $N$ of similar cells is now connected in series with a wire of the same material and cross-section but of length $2\ L$. The temperature of the wire is raised by the same amount $\Delta\ T$ in the same time. The value of $N$ is

  1. $4$
  2. $6$
  3. $8$
  4. $9$
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice physics chemical effects of electric current study about cells electric cell types of cells

Two cells of emf's $3V$ and $3V$ have internal resistances  $1.5\Omega\ &\ 1\Omega$ are connected in parallel across $3\Omega,$ such that they send the current through $3\Omega$ in same direction calculate the p.d. across $3\Omega$ resistor.

  1. 3V

  2. 4V

  3. 1.5V

  4. 2.5V
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Two cells of emf 3V with internal resistances 1.5 ohm and 1 ohm are connected in parallel, so their equivalent emf E_eq = (E1/r1 + E2/r2) / (1/r1 + 1/r2) = (3/1.5 + 3/1) / (1/1.5 + 1/1) = (2 + 3) / (2/3 + 1) = 5 / (5/3) = 3V. The equivalent internal resistance r_eq = (1.5 * 1) / (1.5 + 1) = 1.5 / 2.5 = 0.6 ohm. When connected across a 3 ohm resistor, the potential difference is V = E_eq * R / (R + r_eq) = 3 * 3 / (3 + 0.6) = 9 / 3.6 = 2.5V.

Multiple choice physics chemical effects of electric current study about cells electric cell types of cells

Why the bulb brighter in a simple circuit that has more cells?

  1. Because the flow of electricity is more

  2. Because the flow of electricity is same

  3. Because the flow of electricity is less

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Adding more cells in series increases the total voltage of the circuit, which increases the current flowing through the bulb, making it brighter.

Multiple choice physics chemical effects of electric current study about cells electric cell types of cells

A cell in which chemical energy is converted into electric energy by first passing a current through it is called a _________.

  1. Primary cell

  2. Secondary cell

  3. Photocell

  4. Electrostatic machine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cell in which chemical energy is converted into electrical energy is called a primary cell. Leclanche cell, Daniel cell, Voltaic cell are all primary cells and not the storage cells.

Multiple choice physics chemical effects of electric current study about cells electric cell types of cells

In torch light cell is used as source of which energy ?

  1. Electrical Energy

  2. Mechanical Energy

  3. Chemical Energy

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In torch light, cell is used as a source of electrical energy.

As electrical cell internally converts stored chemical energy into electrical energy, allowing a current to flow from the positive terminal round to the negative one via an external circuit .