List of top Physics Questions

Power dissipated across the 8 Ω resistor in the circuit shown here is 2 W. The power dissipated in watt units across the 3 Ω resistor is:
Power dissipated across the 8 Ω resistor in the circuit
In producing chlorine through electrolysis 100 W power at 125 V is being consumed. How much chlorine per min is liberated? ECE of chlorine is 0.367 x 10-6 kg/C:
In the circuit shown, if a conducting wire is connected between points A and B, the current in this wire will:
circuit shown, if a conducting wire is connected between points A and B, the current in this wire will
The potential energy of a long spring when stretched by 2 cm is U. If the spring is stretched by 8 cm the potential energy stored in it is:
A parallel plate air capacitor is charged to a potential difference of V volts. After disconnecting the charging battery the distance between the plates of the capacitor is increased using an insulating handle. As a result the potential difference between the plates:
300 J of work is done in sliding a 2 kg block up an inclined plane of height 10 m. Taking g =10 m/s2, work done against friction is :
When a charged particle moving with velocity is subjected to a magnetic field of induction \(\rightarrow\) B , the force on it is non-zero. This implies that :
A point object is placed at a distance of 20 cm from a thin planoconvex lens of focal length 15 cm. The plane surface of the lens is now silvered. The image created by the system is at
A 0.5 kg ball moving with a speed of 12 m/s strikes a hard wall at an angle of 30° with the wall. It is reflected with the same speed and at the same angle. If the ball is in contact with the wall for 0.25 s, the average force acting on the wall is :
A microscope is focused on a mark on a piece of paper and then a slab of glass of thickness 3 cm and refractive index 1.5 is placed over the mark. How should the microscope be moved to get the mark in focus again?
A transistor is operated in common emitter configuration at constant collector voltage VC = 1.5 V such that a change in the base current from 100 µA to 150 µA produces a change in the collector current from 5 mA to 10 mA. The current gain (β) is :
In a discharge tube ionization of enclosed gas is produced due to collisions between :
A forward biased diode is :
Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic radiation of photon energy 12.1 eV. According to Bohr's theory, the spectral lines emitted by hydrogen will be :
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the decay constant of the material is \(\lambda\), then :
A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of frequency f. If L is doubled and C is changed to 4C, the frequency will be :
Refractive index of ionosphere is
Circular loop of a wire and a long straight wire carry currents $I _{ c }$ and $I _{ e }$, respectively as shown in figure. Assuming that these are placed in the same plane. The magnetic field will be zero at the centre of the loop when the separation $H$ is :
When a spring is stretched by a distance $x$, it exerts a force, given by $F = (-5x - 16x^{3})\, N$. The work done, when the spring is stretched from $0.1 \,m$ to $0.2\, m $ is
The $(x, y, z)$ coordinates of two points $A$ and $B$ are given respectively as $(0, 3,-1)$ and $(-2, 6, 4)$. The displacement vector form $A$ to $B$ may be given by:
A wire of resistance 5 ohms is stretched such that longitudinal strain is $200 \%$.The new resistance in ohms is
A slit of width 0.1 mm is illuminated normally d by light of $\lambda = 5000 \mathring A $. Diffraction bands are observed on a screen, 1 m away from the slit. Third dark band is at a distance x from the central maximum. x is approximately
Two bars of radius r and 2rare kept in contact as shown. An electric current I is passed through the bars. Which one of following is correct ?
A galvanometer has a resistance $ 50\,\Omega $ . A resistance of $ 5\,\Omega $ is connected parallel to it. Fraction of the total current flowing through galvanometer is
What is the potential drop between points $A$ and $C$ in the following circuit? Resistances $ 1 \omega $ and $ 2 \omega $ are represent the internal resistance of the respective cells.