You might have a flashlight that runs (2) d-cells of 1.5 volts each in series. the bulb is rated for 0.7 amps. what’s its resistance?

The value of resistance is 4.28 Ω.

Explanation:

Voltage of single d-cells = 1.5 V

Two d-cells are in series with in a flashlight.

(series arrangement)

So, Total voltage in the flash light:

V = 1.5 V + 1.5 V = 3.0 V

Electrical Current rating of the bulb I= 0.7 A

let the resistance be R

(Ohms law}

The value of resistance is 4.28 Ω.

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).