HomeWork Help: What is the current in the bulb..

Q) A 100 W lightbulb is plugged into a standard 120 V outlet. (a) How much does it
cost per 31-day month to leave the light turned continuously? Assume electrical
energy costs US$0.06/kWh. (b) What is the resistance of the bulb? (c) What is the current in the bulb?

Sol:

First let us find the energy used in 31 days is(in kWh) and then let go for calculating the cost.

a) U = P * t = 0.100kW * 31days * 24hrs/day

       = 74.4kWh

Cost per 31 day month = 74.4kW h * $0.06/kW h

  = $4.464

b) The resistance of the bulb is given by,

P = V²/R

R = V²/P

  = (120V)²/100W

=144Ω

c) The current in the bulb is given by,

P = VI

I = P/V

     = 100W/120V

 = 0.833 A

Assignment Help: How much thermal energy is produced in..

Q) A 1250 W radiant heater is constructed to operate at 115 V. (a) What is the current in
the heater when the unit is operating? (b) What is the resistance of the heating coil? (c)
How much thermal energy is produced in 1.0 h?

Sol:

a) We can calculate the current ‘I’ from the power and voltage.

P = IV

I = P/V

= 1250/115

=10.87A

b) We can calculate the Resistance ‘R’ from the Voltage and power

P = V²/R

R = V²/P

= (115)²/1250

=10.58ohms

c) Thermal energy ‘U’ produced in 1 hr=3600secs is given by,

U = P * t =1250 *3600 = 4.5 *10⁶J

Biology Homework: Where will protein synthesis be completed..

Q) If a protein is going to be secreted where will protein synthesis be completed?

Sol:

Protein synthesis is the process where proteins are synthesized or produced in the living things as per the directions given by DNA (deoxyribonucleic acid) and processed by RNA (ribonucleic acid) and many other proteins.

If a protein is going to be secreted then the protein synthesis will be completed on ribosomes within these organelles and are distributed directly into various parts within the same organelles.