Email

Chat with tutors

Login

Ask Questions, Get Answers

Menu X

home ask tuition questions practice papers mobile tutors pricing

X

Recent questions tagged electrical-energy-and-power

Two bulbs consume same power when operated at $200V\: and\: 300V$ respectively. When these bulbs are connected in series across a $DC$ supply of $500V$, then consider the following statements

asked Feb 16, 2014 by thanvigandhi_1

1 answer

Three wires of the same material are connected in parallel to a source of emf. Their lengths are in the ratio 1 : 2 : 3 and cross-sectional areas are in the ratio 2 : 4 : 1. Then, the ratio of power dissipated across them will be

asked Feb 16, 2014 by thanvigandhi_1

1 answer

The electrochemical equivalent of a metal is $ 3.3 \times 10^{−7}$ at the cathode when a $3\: A$ current is passed for 2 seconds will be kg per coulomb. The mass of the metal liberated

asked Feb 16, 2014 by thanvigandhi_1

1 answer

Time taken by a $836\: W$ heater to heat one liter of water from $10^{\circ}C\: to\: 40^{\circ}C$ is

asked Feb 16, 2014 by thanvigandhi_1

1 answer

A battery is used to charge a parallel plate capacitor till the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and the work done by the battery will be

asked Feb 16, 2014 by thanvigandhi_1

1 answer

An electric bulb is rated $220V$- $100W$. The power consumed by it when it operates on $110V$ is

asked Feb 16, 2014 by thanvigandhi_1

1 answer

The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100W and 200V lamp when not in use?

asked Feb 15, 2014 by thanvigandhi_1

1 answer

A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

asked Feb 15, 2014 by thanvigandhi_1

1 answer

Two points $P$ and $Q$ are maintained at the potentials of $10V$ and $-4V$ respectively. The work done in moving $100$ electrons from $P$ to $Q$ is

asked Feb 13, 2014 by thanvigandhi_1

1 answer

Two resistors R and 2R are connected in parallel in a circuit. The thermal energy developed in R and 2R are in the ratio

asked Feb 13, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: $40W$ tube light appears brighter than a $40W$ bulb.\[\] Statement2: Light sources having same power rating appear to glow equally brightly

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Which of these is correct for each pair of statements? \[\] Statement 1: Resistance of $50W$ bulb is greater than that of a $100W$ bulb. \[\] Statement 2: Resistance of a bulb is inversely proportional to rated power.

asked Feb 10, 2014 by thanvigandhi_1

1 answer

Three resistances $ R, 2R$ and $3R$ are connected in parallel to a battery. Then

asked Feb 10, 2014 by thanvigandhi_1

1 answer

A battery of internal resistance $2 \Omega$ is connected to a variable resistor whose value can be varied from $ 4\Omega\: to\: 10\Omega$. If the variable resistance is gradually increased from an initial value of $4\Omega$, the power consumed by it:

asked Feb 10, 2014 by thanvigandhi_1

1 answer

A battery is supplying power to a tape-recorder by cable of resistance $0.02\Omega$. If the battery is generating $50W $ at $5V$, the power received by the tape-recorder is:

asked Feb 10, 2014 by thanvigandhi_1

1 answer

A constant voltage is applied to the two ends of a uniform metallic wire. Some heat is produced in it. The heat developed is doubled if

asked Feb 8, 2014 by thanvigandhi_1

1 answer

The supply voltage to a room is $120\: V\: DC$. The resistance of the lead wires is $6 \Omega$. A $60\: W$ bulb is already switched on. What is the decrease of voltage across the bulb, when a $240\: W$ heater is switched on in parallel to the bulb?

asked Feb 8, 2014 by thanvigandhi_1

1 answer

Two electric bulbs marked $25W – 220V$ and $100W – 220V$ are connected in series to a $440V$ supply. Which of the bulbs will fuse?

asked Feb 8, 2014 by thanvigandhi_1

1 answer

A rigid container with thermally insulated walls contains a coil of $100 \Omega$ resistance with a current of $1A$. Change in internal energy after 5 min will be

asked Feb 8, 2014 by thanvigandhi_1

1 answer

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 are now connected in series with a wire of the same material and cross-section but of length $2L$. The temperature is raised by the same amount $ \Delta T$ in the same time. The value of $N$ is

asked Feb 8, 2014 by thanvigandhi_1

1 answer

In steady state, a resistor is carrying a current $i$. The power lost to the surroundings is $b(T- T_0)$. Here $b$ is a constant, $T$ is the temperature of the resistance and $T_0$ is the surrounding temperature. If the coefficient of linear expansion is $ \alpha$. The strain in the wire is

asked Feb 8, 2014 by thanvigandhi_1

1 answer

To see more, click for the full list of questions or popular tags.

Feedback Terms Facebook Twitter About Us

Your payment for is successful.

...