Question

Find the position of the object when an image is formed in front of a mirror on a screen at a distance of 30cm from the mirror. The focal length of the mirror is 10cm. Calculate magnification​

Answer 1

AnswEr :

Given that ,

The two resistor 35 ohm and 14 ohm are connected in parrallel combination with 7 v battery

We know that , the equivalent resistance in parrallel combination is given by

$\large \rm \fbox{ \frac{1}{R } = \frac{1}{R_{1}} + \frac{1}{R_{2}} + ... + \frac{1}{R_{n}} }$

Thus ,

$\sf \mapsto \frac{1}{R} = \frac{1}{35} + \frac{1}{14} \\ \\ \sf \mapsto \frac{1}{R} = \frac{14 + 35}{490} \\ \\ \sf \mapsto R = \frac{490}{49} \\ \\ \sf \mapsto R =10 \: \: ohm$

$\therefore \sf \underline{The \: equivalent \: resistance \: is \: 10 \: ohm}$

We know that ,

$\large \rm \star \: \: \fbox{V = IR} \: \: \{ \because \: Ohm's \: law\}$

Thus , the current in each resistor will be

7 = I × 35

I = 0.2 amp

And

7 = I × 14

I = 0.5 amp

$\therefore \sf \underline{The \: current \: in \: each \: resistor \: are \: 0.2 \: amp \: and \: 0.5 \: amp}$

Now , the net current will be

7 = I × 10

I = 0.7 amp

$\therefore \sf \underline{The \: net \: current \: is \: 0.7 \: amp }$

Answer 2

The Current will be of O.7 amp