English
Karnataka Board PUCPUC Science Class 11

Is Energy Produced When a Transformer Steps up the Voltage?

Advertisements
Advertisements

Question

Is energy produced when a transformer steps up the voltage?

Short/Brief Note
Advertisements

Solution

When a transformer steps up the voltage, the voltage increases but current decreases. Neglecting any loss of energy, the power remains constant and, hence, energy is not produced. It remains constant.

shaalaa.com
  Is there an error in this question or solution?
Chapter 39: Alternating Current - Short Answers [Page 329]

APPEARS IN

HC Verma Concepts of Physics Volume 1 and 2 [English]
Chapter 39 Alternating Current
Short Answers | Q 10 | Page 329

RELATED QUESTIONS

A current i1 = i0 sin ωt passes through a resistor of resistance R. How much thermal energy is produced in one time period? A current i2 = −i0 sin ωt passes through the resistor. How much thermal energy is produced in one time period? If i1 and i2 both pass through the resistor simultaneously, how much thermal energy is produced? Is the principle of superposition obeyed in this case?


A capacitor acts as an infinite resistance for ______.


The peak voltage of a 220 V AC source is


An AC source is rated 220 V, 50 Hz. The average voltage is calculated in a time interval of 0.01 s. It


A transformer has 50 turns in the primary and 100 in the secondary. If the primary is connected to a 220 V DC supply, what will be the voltage across the secondary?


Compare resistance and reactance.


Suppose the initial charge on the capacitor is 6 mC. What is the total energy stored in the circuit initially? What is the total energy at later time?


Average power supplied to a capacitor over one complete cycle is ______.


Of the following about capacitive reactance which is correct?

A device ‘X’ is connected to an a.c source. The variation of voltage, current and power in one complete cycle is shown in figure.

  1. Which curve shows power consumption over a full cycle?
  2. What is the average power consumption over a cycle?
  3. Identify the device ‘X’.


In the LCR circuit shown in figure, the ac driving voltage is v = vm sin ωt.

  1. Write down the equation of motion for q (t).
  2. At t = t0, the voltage source stops and R is short circuited. Now write down how much energy is stored in each of L and C.
  3. Describe subsequent motion of charges.


Define Capacitive reactance.


An iron cored coil is connected in series with an electric bulb with an AC source as shown in figure. When iron piece is taken out of the coil, the brightness of the bulb will ______.


A resistor of 50 Ω, a capacitor of `(25/pi)` µF and an inductor of `(4/pi)` H are connected in series across an ac source whose voltage (in volts) is given by V = 70 sin (100 πt). Calculate:

  1. the net reactance of the circuit
  2. the impedance of the circuit
  3. the effective value of current in the circuit.

An AC source is connected to a capacitor C. Due to decrease in its operating frequency ______.


A 40 µF capacitor is connected to a 200 V. 50 Hz ac supply. The rms value of the current on the circuit is, nearly ______.


In an ac circuit an alternating voltage e = 200\[\sqrt 2\] sin100t volts is connected to capacitor of capacity 1 µF. The r.m.s. value of the current in the circuit is ______.


The resistance of a coil for d.c. is 5 Ω. In a.c., the resistance will ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×