Question
If the distance between a point source and screen is doubled, then intensity of light on the screen will become(a) Four times(b) Double(c) Half (d) One-fourth
✓
Answer
(d) One-fourth
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A 2 volt battery, a 15 Ω resistor and a potentiometer of 100 cm length, all are connected in series. If the resistance of potentiometer wire is 5 Ω, then the potential gradient of the potentiometer wire is(a) 0.005 V/cm(b) 0.05 V/cm(c) 0.02 V/cm(d) 0.2 V/cm
A lamp whose resistance is $280 \Omega$ is joined with an ac source of 200 V . The peak value of current flowing in the lamp is :
→Consider the situation shown in figure. The wire AB is slid on the fixed rails with a constant velocity. If the wire AB is replaced by a semicircular wire, the magnitude of the induced current will:
- Increase.
- Remain the same.
- Decrease.
- Increase or decrease depending on whether the semicircle bulges towards the resistance or away from it.
The magnetic flux linked with a coil is given by an equation $\emptyset ($in webers$) = 8 t^2+3 t+5.$ The induced $e.m.f.$ in the coil at the fourth second will be
→According to the pulsating theory the expansion and contraction of the universe repeats after every (a) 11 years(b) 8 billion years(c) 8 million years(d) 80 billion years
If $l_2$ and $l_2$ be the size of the images respectively for the two positions of lens in the displacement method, then the size of the object is given by
→Complete the following statements with an appropriate word/ term be filled in the blank space(s).
The force of attraction or repulsion between two charges is given by ......................
The force of attraction or repulsion between two charges is given by ......................
Assertion : Fax is a modulating and demodulating device.
Reason : It is necessary for exact reproduction of a document.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.
Reason : It is necessary for exact reproduction of a document.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.
Under what condition will the strength of current in a wire of resistance R be the same for connection is series and in parallel of n identical cells each of the internal resistance r?
The current carrying wire and the rod $AB$ are in the same plane. The rod moves parallel to the wire with a velocity $v.$ Which one of the following statements is true about induced emf in the rod
→