Physics

The force which keeps a body moving in a circular path is called:

The center of gravity of a triangular lamina (triangle) is at the point of intersection of its:

A force $F$ acts on a body and displaces it by a distance $s$ at an angle $\theta$ to the force. The work done $W$ is:

One calorie is approximately equal to:

The total energy of a freely falling body:

In a block and tackle system with 5 pulleys, if the effort applied is $100\ N$ and the efficiency is $80\%$, find the load lifted.

A nutcracker is an example of a lever where:

A man of mass $70\ kg$ climbs up a ladder of $5\ m$ length, which makes an angle of $60^\circ$ with the horizontal. The work done by the man against gravity is: ($g = 10\ m/s^2$)

A body of mass $10\ kg$ is moving with a constant velocity of $5\ m/s$. A constant force of $20\ N$ is applied on it for $2\ seconds$ in the direction of its motion. The change in kinetic energy is:

When a spring is stretched by a distance $x$, the potential energy stored in it is $V$. When it is stretched by $2x$, the potential energy stored will be:

The angle of refraction for a ray passing from air to glass is $30^\circ$. If the refractive index of glass is $1.5$, what is $\sin i$?

If the refractive index of a medium is $1.0$, it means light travels:

Which of the following materials has the highest refractive index?

For a prism in the position of minimum deviation, the angle of incidence is:

If $n_{12}$ is the refractive index of medium 2 with respect to medium 1 and $n_{23}$ is the refractive index of medium 3 with respect to medium 2, then the refractive index of medium 3 with respect to medium 1 ($n_{13}$) is:

A ray of light passes from air to a medium of refractive index 1.414. If the angle of incidence is $45^{\circ}$, what is the value of the angle of refraction?

How does the speed of light change when it travels from a medium of refractive index 1.2 to another medium of refractive index 1.5?

A ray of light is incident from air onto a parallel-sided glass slab of thickness $t$ and refractive index $n$ at a very small angle of incidence $i$. Using the small-angle approximations $\sin \theta \approx \theta$ and $\cos \theta \approx 1$, which of the following expressions correctly represents the lateral displacement $d$ of the emergent ray?

A point object is placed at a distance of $12\text{ cm}$ from a glass slab of thickness $3\text{ cm}$ and $n=1.5$. The image of the object as seen through the slab is formed at a distance of:

The angle of a prism is $A$. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence $2A$ on the first surface return through the same path after suffering reflection at the silvered surface. The refractive index of the prism is:

In a convex lens, when the object is placed between $F$ and $2F$, the image is formed:

If two lenses of power $P_1$ and $P_2$ are placed in contact, the total power $P$ of the combination is:

A lens has two spherical surfaces. The line joining the centers of curvature of these surfaces is called the:

When light travels from glass to air, it bends:

When a lens is split into two equal halves along the principal axis, the focal length of each half:

A concave lens of focal length $15\text{ cm}$ forms an image $10\text{ cm}$ from the lens. The object distance is:

A point object is placed at a distance of $10\text{ cm}$ from a convex lens of focal length $10\text{ cm}$. The image is formed at:

A lens has a power of $+2.0\text{ D}$ in air. When immersed in a liquid of refractive index $1.5$, its power becomes $-0.5\text{ D}$. The refractive index of the lens material is:

Two points $P$ and $Q$ are at distances $9\text{ cm}$ and $16\text{ cm}$ from a convex lens on the same side. If the magnification is same in both cases (one real, one virtual), the focal length of the lens is:

A thin convex lens of focal length $10\text{ cm}$ is placed in contact with a thin concave lens of focal length $15\text{ cm}$. An object is placed at $30\text{ cm}$ from the combination. The final image is:

Which scientist discovered infrared radiation by using a thermometer?

Electromagnetic waves are ________ in nature.

Which radiation is used for taking photographs in the dark or in smoky conditions?

The wavelength of infrared radiation is:

The angular dispersion between two colors depends on:

Which of the following represents the correct order of decreasing energy of photons?

The phenomenon of scattering of light depends on the size of the scattering particles. If the size of the particles ($a$) is much smaller than the wavelength ($\lambda$), the intensity of scattered light follows:

A composite beam consisting of three monochromatic lights—Red, Green, and Violet—is incident normally on one of the shorter faces of a right-angled isosceles glass prism. The refractive indices of the prism material for these colors are $1.39$, $1.44$, and $1.47$ respectively. Given that the ray is incident on the hypotenuse from within the prism at an angle of $45^\circ$, which of these colors will successfully emerge from the hypotenuse face into the air?

What is the effect on the deviation produced by a prism if the temperature of the prism increases?

Why are clouds generally seen as white?

Sound waves cannot be polarized because they are:

The maximum displacement of a vibrating particle from its mean position is:

The ratio of the speed of sound in air to the speed of sound in water is:

Which factor does NOT affect the speed of sound in a gas?

When a body performs damped vibrations, what happens to the total energy of the system?

Which of the following properties of sound depends on its frequency?

The total distance travelled by a sound wave to hear an echo from a wall at distance $d$ is:

A wave moves from a denser medium to a rarer medium. Which of the following is true about its velocity and wavelength?

If the length of a sonometer wire is increased by $20\%$ and the tension is increased by $44\%$, the fundamental frequency will:

The loudness of sound depends on the amplitude $A$ and the distance $r$ from the source. How does the intensity $I$ vary with these parameters?

One Ampere of current is defined as the flow of:

The potential difference across the neutral wire in a standard Indian household supply is ideally:

Which component is used to prevent an electric shock if the metallic body of an appliance becomes live?

If two identical resistors of $1 \Omega$ each are connected in series, the total resistance is:

A fuse is a safety device which is always connected in _______ with the _______ wire.

The energy dissipated as heat in a conductor of resistance $R$ when a current $I$ flows through it for time $t$ is given by:

What happens to the total resistance of a circuit when an additional resistor is connected in parallel to the existing circuit?

A $100 \Omega$ resistor and a $200 \Omega$ resistor are connected in series to a $300 V$ source. A voltmeter of resistance $200 \Omega$ is connected across the $100 \Omega$ resistor. The reading of the voltmeter will be:

Which of the following graphs correctly represents the variation of resistivity $\rho$ with temperature $T$ for a semiconductor?

Three identical resistors are first connected in series and then in parallel. The ratio of equivalent resistance in series to that in parallel is:

Switches are always connected to which wire in a circuit?

What does the 'kWh' (kilowatt-hour) measure in a household?

In a three-pin plug, why is the Earth pin made longer and thicker than the others?

A fuse wire should possess which of the following properties?

A dual-control switch (staircase wiring) consists of which type of switches?

An appliance has a resistance of $100\, \Omega$ and is connected to a $220\text{ V}$ supply. What is the power consumed by it?

In an electrical socket, why is the Neutral terminal connected to the Earth at the local substation?

In a dual-control staircase lighting system, a bulb is controlled by two two-way switches ($S_1$ at the bottom and $S_2$ at the top). If the system is wired such that the bulb only glows when both switches are in the 'UP' position or both are in the 'DOWN' position, and a fault occurs where the 'intermediate' wire $L_1$ is severed, which of the following describes the resulting behavior of the lamp?

A homeowner notices that when a heavy-duty air conditioner ($2200\text{ W}$) and a microwave ($1100\text{ W}$) are both running on the same $220\text{ V}$ radial circuit, the voltage drop across the line becomes significant. If the total resistance of the live and neutral wires connecting the distribution board to the kitchen socket is $0.5\text{ }Ω$, calculate the actual voltage available at the appliances when both are operating simultaneously.

An industrial kitchen is being wired with three high-power heating elements, each rated at $2.2\text{ kW}, 220\text{ V}$. The electrician decides to connect them all in parallel to a single circuit breaker. To ensure safety and prevent the insulation from melting due to overheating, a fuse must be selected. Considering the total current drawn when all elements are active and a safety margin of $20\%$, which fuse rating is most appropriate for this specific sub-circuit?

Which of the following is an application of an electromagnet?

In the Right-Hand Thumb Rule, the curled fingers indicate the direction of:

Magnetic field lines inside a bar magnet travel from:

A device that converts electrical energy into mechanical energy is a:

A student connects a $12\text{ V}$ DC battery to the primary coil of a transformer as shown in the diagram. If the primary coil has $100$ turns and the secondary coil has $20$ turns, what will be the steady-state voltage measured across the secondary coil?

In a step-down transformer, if the input voltage is $220\text{ V}$ and the output voltage is $11\text{ V}$, the turns ratio ($N_p/N_s$) is:

An AC generator is based on the phenomenon of:

Self-induction is often called the 'inertia of electricity' because it:

A circular wire loop of radius $r$ is placed in a region of uniform magnetic field $B$ such that the plane of the loop is perpendicular to the field. If the radius of the loop starts shrinking at a constant rate $k$, the induced EMF in the loop is:

The use of a 'Commutator' in a DC generator is to:

The process of a solid directly changing into gas without passing through the liquid state is:

A substance $A$ has a specific heat capacity of $400 \text{ J kg}^{-1} \text{ K}^{-1}$ and substance $B$ has $900 \text{ J kg}^{-1} \text{ K}^{-1}$. For the same mass and same heat input:

Ice at $0^{\circ}\text{C}$ is more effective in cooling a drink than water at $0^{\circ}\text{C}$ because:

Which of the following is NOT a unit of energy?

Three liquids A, B, and C of equal mass are kept in identical containers and heated to a temperature of $90^{\circ}C$. They are then allowed to cool down to $40^{\circ}C$ in the same surroundings. The diagram below illustrates the time taken by each liquid to undergo this temperature change. Based on this information, which liquid possesses the highest specific heat capacity?

Calculate the heat energy required to raise the temperature of $2\text{ kg}$ of iron from $25^{\circ}C$ to $75^{\circ}C$. (Specific heat of iron $= 480\text{ J/kg}^{\circ}C$)

If a substance has a high specific heat capacity, it means:

Which of the following has the highest specific heat capacity?

A block of metal is heated by a $12\text{ W}$ heater for $5\text{ minutes}$. The temperature increases from $25^{\circ}C$ to $45^{\circ}C$. If the mass of the block is $400\text{ g}$, find its specific heat capacity.

If $50\text{ g}$ of water at $20^{\circ}C$ is mixed with $50\text{ g}$ of water at $80^{\circ}C$, and $10\text{ g}$ of ice at $0^{\circ}C$ is then added, the final temperature will be approximately:

In the context of radioactivity, background radiation is present:

Where should radioactive waste ideally be disposed of?

A substance that spontaneously emits radiations is said to be:

Which device is commonly used to detect and measure radioactivity?

Which of these is a safe way to handle a radioactive source in a school laboratory?

The process by which an unstable nucleus becomes stable by the spontaneous emission of radiations is known as:

Which of the following symbols is used to warn people about the presence of radioactive materials?

If a nucleus $_{88}^{226}Ra$ emits an alpha particle, what is the ratio of neutrons to protons in the daughter nucleus?

In a nuclear equation $_{Z}^{A}X \rightarrow _{Z+1}^{A}Y + e^- + \bar{\nu}$, the particle $\bar{\nu}$ is an antineutrino. What is its primary role in the decay process?

Which of the following can stop a high-energy beta particle but not a gamma ray?