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A current of 5 A flows through a conductor having resistance 2Ω . The potential difference (in volt) across the ends of the conductor is?
A beam of white light undergoes dispersion through a triangular glass prism forming a band of seven colours. Which of the statements is/are correct?
- a) The red-coloured component has minimum refractive index.
- (b) The violet-coloured component deviates the least.
- (c) All components of white light have same speed in glass.
A current of 5 A flows through an electrical appliance when the potential difference of 50 V is applied across its terminals. What will be the current drawn by the appliance if the potential difference is increased to 110 V?
According to Fleming's right-hand rule, the index finger and the central finger of the right hand represent directions of ______and _________respectively?
If a coil of a conductor with 50 Ω resistance is subjected to time varying magnetic field such that the EMF induced is 5 V, then the induced current in the coil is?
An electric heater rated 1000 W is used for 5 hours daily. For cost per unit of ₹6.00,calculate the total cost for running the device for the month of September (in ₹)?
The phenomenon due to which the relative motion between a conductor and a magnet produces a potential difference across the conductor is called?
Which of the following statements is/are correct?
- (A) Resistance is independent of temperature.
- (B) The more the voltage across a conductor, the more is the resistance.
- (C) The S.I unit of resistance is ohm.
Identify the INCORRECT relation between power (P). Current(I), Resistance (R) and potential difference (V)?
Which of the following statements is are true for a number of resistors connected in parallel combination?
- (1) All the resistors are connected between two given points.
- (ii) The equivalent resistance of the circuit is more than the individual resistance.
- (iii) The potential difference across each resistor is same.
The magnification produced by a lens is 1/2. The nature and the relative size of the image formed by the lens in the respective order is?
Three bulbs A, B and C rated 40 W, 60 W and 100 W, respectively, are connected in parallel to a voltage source of 220 V. The bulb that glows with maximum brightness is?
Which of the following materials is preferably used in making heating elements of electrical heating devices?
Two resistors of 4Ω each are connected in parallels to a 5 V battery source. The total current in the circuit is?
A wire of a given material has length '1' and resistance 'R'. Another wire of the same material having nine times the length and the same area of cross section will have a resistance equal to?
An electric heater is rated 2200 W at 220 V. The minimum rating of the fuse wire to be connected to the device is?
Which of the following is/are useful effort(s) for sustainability of resources?
- a. Switching off unnecessary lights and fans
- b. Using lift instead of stairs
- c. Repairing leaking taps for conserving water
- d. Using empty containers to store things
- e. Going to school by your own car instead of cycling
A magnet, when moved near a coil, produces an induced potential difference in the coil, What happens when we increase the speed of the magnet near the coil?
Two wires A and B are made of same material and have the same length but different cross-sectional areas. If the resistance. of wire A is 9 times the resistance of wire B, the ratio of the radius of wire A to that of wire B is?
Which of the following statements is/are correct?
- (i) Magnetic field strength is strongest at the centre of a bar magnet.
- (ii) No two magnetic field lines can intersect.
- (iii) Magnetic field lines always form closed continuous curves.
A boy focusses a sharp image of a distant object on a screen using a lens. The distance between the approximately equal to?
Which of the following statements are correct?
- (a). For a lens the first principal focus is the position of the object whose image is at infinity
- (b) For a lens the first principal focus is the position of the object whose image is formed at twice the focal length.
- (c) For a lens the second principal focus is the position of the real image whose object is at infinity
- (d) For a lens the second principal focus is the position of the object whose image is formed at twice the focal length
A wire of a given material has length "I' and resistance "R". Another wire of the same material having three times the length and twice the area of cross section will have a resistance equal to:
There are four different points on a plane such that no three are collinear. The number of distinct straight lines that can be drawn through them is?
An object placed at a distance of 25 cm from a converging lens forms a real and inverted image at 30 cm from the lens. The magnification produced by the lens is equal to:
In accordance with Fleming’s left hand rule used to find the force on a current-carrying conductor placed inside a magnetic field, the thumb and the index finger represent the directions of …………… and …………… , respectively?
Which of the following types of images can be obtained on a screen?
- (a) Real and enlarged
- (b) Real and diminished
- (c) Virtual and enlarged
- (d) Virtual and diminished
Which of the following statements is/are correct for a current-carrying solenoid?
- (i) It can be used to magnetize a piece of soft iron.
- (ii) It acts like a bar magnet.
- (iii) The field lines are concentric circles